DIY Roof rack for M3/M4 with CF roof

[Mantvis]

this would happen only with my luck...
as soon as i took the cover screw/bolt out, the thread fell inside the roof panel...

[humbertin0]

Originally Posted by Mantvis

this would happen only with my luck...
as soon as i took the cover screw/bolt out, the thread fell inside the roof panel...

Are you saying that the threaded portion of the bolt fell inside? The bolt sheared off? Im trying to understand what fell inside.

[Mantvis]

the bolt came out nicely, but i guess the thread it self is a plate that is welded or gluded to the body. as soon as i took the bolt out the thread plate fell inside the body of the car.

[x.shell]

Originally Posted by Mantvis

this would happen only with my luck...
as soon as i took the cover screw/bolt out, the thread fell inside the roof panel...

Yikes.

Did you end up fishing it out?

It also looks like the imprinted divot on the carbon fiber is way off from where you drilled. How did you find the correct location of the bolt?

[Mantvis]

Originally Posted by exo-shell

Yikes.

Did you end up fishing it out?

It also looks like the imprinted divot on the carbon fiber is way off from where you drilled. How did you find the correct location of the bolt?

Not able to fish it out, the thread part is too big to fit through the hole, it was secured to the panel from inside.
No more roof rack for me, ended up pouring a tube of silicone inside that way it does not rattle

If you look at the first picture that I posted, you can see a "dip" in the carbon fiber on the outside of the roof. you have to find the middle and drill and pray for the best..

[x.shell]

Originally Posted by Mantvis

Not able to fish it out, the thread part is too big to fit through the hole, it was secured to the panel from inside.
No more roof rack for me, ended up pouring a tube of silicone inside that way it does not rattle

If you look at the first picture that I posted, you can see a "dip" in the carbon fiber on the outside of the roof. you have to find the middle and drill and pray for the best..

Damn. That's some bad luck. I think it's really odd that the inner thread isn't somehow secured to the body. It's so strange.

[Penguinman87]

I found it strange as well that the thread part was able to move after removing the plug. I didn't think much of it at the time and just went about it carefully so it doesn't move out of place. That's some horrible luck.

[Mr. Big]

I'm wondering why BMW put the trap doors along the railings and didn't allow for mounting points underneath.

And can someone tell me what this picture is from the 1st post in this thread?

[Penguinman87]

Originally Posted by Mantvis

this would happen only with my luck...
as soon as i took the cover screw/bolt out, the thread fell inside the roof panel...

Taking another look at your pics it looks normal. The threaded portion does move inside just align it with the mounting bolt and it should be able to be tightened.

[jwzimm]

Originally Posted by Mantvis

Not able to fish it out, the thread part is too big to fit through the hole, it was secured to the panel from inside.
No more roof rack for me, ended up pouring a tube of silicone inside that way it does not rattle

Well that sucks. You were fine and could have proceeded with installation of the mounting studs. The threaded portion you are referring to is known as a "nutplate". It is designed to float so that when the fastener comes in it will align easily and allow it to torque up. If you can remove that silicone try threading in the mounting stud and see if it will torque up.

Originally Posted by Mantvis

If you look at the first picture that I posted, you can see a "dip" in the carbon fiber on the outside of the roof. you have to find the middle and drill and pray for the best..

This is what freaks me out about all of this. There is not good data on the exact position of those mount points so you have to guess and check. If someone is able they should take some accurate measurements from a known point (fwd/aft edge of the roof panel for example) so others can mark out that center point and drill without error.

[Mantvis]

Originally Posted by jwzimm

Well that sucks. You were fine and could have proceeded with installation of the mounting studs. The threaded portion you are referring to is known as a "nutplate". It is designed to float so that when the fastener comes in it will align easily and allow it to torque up. If you can remove that silicone try threading in the mounting stud and see if it will torque up.



This is what freaks me out about all of this. There is not good data on the exact position of those mount points so you have to guess and check. If someone is able they should take some accurate measurements from a known point (fwd/aft edge of the roof panel for example) so others can mark out that center point and drill without error.

It well down into the pillar, and flipped upside down. Was able to get it up but had no way of geting it to its place, since the bolts i,had were not lomg enough :/

That is my only car, so also ad no way of getting my self to a hardware store .

[jwzimm]

Originally Posted by Mantvis

It well down into the pillar, and flipped upside down. Was able to get it up but had no way of geting it to its place, since the bolts i,had were not lomg enough :/

That is my only car, so also ad no way of getting my self to a hardware store .

Ah, I see. The nut element must have dislodged then. Bummer. I would be concerned about where the element ends up. It may rattle like crazy as it just dropped down onto the headliner. You could probably get it back into position if you drop the headliner.

[Mantvis]

Originally Posted by jwzimm

Ah, I see. The nut element must have dislodged then. Bummer. I would be concerned about where the element ends up. It may rattle like crazy as it just dropped down onto the headliner. You could probably get it back into position if you drop the headliner.

Its not in the headliner, that section is like a tube for structure. Poured quite a bit of silicone to keep in glued that way it does not rattle

[fsujinks]

I had the same thing happen on one of mine. With a little time an Allen wrench and some super glue to get it to stay in place so I could get the screw started. Solid as a rock.

[Maltman]

Originally Posted by Mantvis

this would happen only with my luck...
as soon as i took the cover screw/bolt out, the thread fell inside the roof panel...

I don't know what happen with your thread but this is how this piece is attached in the side panel. It can move left and right but can fall down. Just partly deinstall your roof lining, then you can easily readjust your thread. Don't give up!



Your drilled hole looks very big. Did you drill the side panel?

Originally Posted by Penguinman87

I'm using Thule Aeroblade 43" that came off my e92 M3. Bought the Thule 3028 Podium foot kit to use with the M4. Thule Airscreen wind deflector is 38" version.

Adding on to Maltman's awesome DIY, a T30 torx head is needed to remove the existing plug. Then a 11mm socket is needed to install the new mounting bolts.

Apologies for the bad pictures and dirty car.

Great result - welcome the club

Originally Posted by jwzimm

This is what freaks me out about all of this. There is not good data on the exact position of those mount points so you have to guess and check. If someone is able they should take some accurate measurements from a known point (fwd/aft edge of the roof panel for example) so others can mark out that center point and drill without error.

I tried to make a template, but ... i´ll reinstall the covers and give my best

[Mantvis]

After playing around last night at my friends body shop I was able to get the roof rack on with my buddies help.
What happened was is that drilling though CF roof was not enough. When i went to take the cap bolt out, the side of it got stuck on the pillar and it bent the 2 little arms out and the floater plate fell inside. There was about 1mm that had to be shaven off the aluminum pillar. and it was like that on both passenger mounting points.

[Penguinman87]

Originally Posted by Mantvis

After playing around last night at my friends body shop I was able to get the roof rack on with my buddies help.
What happened was is that drilling though CF roof was not enough. When i went to take the cap bolt out, the side of it got stuck on the pillar and it bent the 2 little arms out and the floater plate fell inside. There was about 1mm that had to be shaven off the aluminum pillar. and it was like that on both passenger mounting points.

Glad it worked out. I would've been so pissed if I couldn't install racks because of that.

[Maltman]

Originally Posted by Mantvis

After playing around last night at my friends body shop I was able to get the roof rack on with my buddies help.
What happened was is that drilling though CF roof was not enough. When i went to take the cap bolt out, the side of it got stuck on the pillar and it bent the 2 little arms out and the floater plate fell inside. There was about 1mm that had to be shaven off the aluminum pillar. and it was like that on both passenger mounting points.

Great!

[pbar]

Originally Posted by jwzimm

This is what freaks me out about all of this. There is not good data on the exact position of those mount points so you have to guess and check. If someone is able they should take some accurate measurements from a known point (fwd/aft edge of the roof panel for example) so others can mark out that center point and drill without error.

Looking at the internal photos with the roof lining removed, would it be possible to drill a pilot hole from the *inside* of the car? (I guess this might destroy the plug making it impossible to remove?)

[Maltman]

Originally Posted by pbar

Looking at the internal photos with the roof lining removed, would it be possible to drill a pilot hole from the *inside* of the car? (I guess this might destroy the plug making it impossible to remove?)

You don't want to remove roof lining - trust me

[x.shell]

Originally Posted by Mantvis

After playing around last night at my friends body shop I was able to get the roof rack on with my buddies help.
What happened was is that drilling though CF roof was not enough. When i went to take the cap bolt out, the side of it got stuck on the pillar and it bent the 2 little arms out and the floater plate fell inside. There was about 1mm that had to be shaven off the aluminum pillar. and it was like that on both passenger mounting points.

Congrats on making it work out. So glad you didn't just give up. The BMW racks might look better if you vinyl wrap the silver part with matte black or something.

Originally Posted by pbar

Looking at the internal photos with the roof lining removed, would it be possible to drill a pilot hole from the *inside* of the car? (I guess this might destroy the plug making it impossible to remove?)

I was thinking this exact same thing. Not only will it be easy to perfectly line up a pilot hole, it'll be easier to catch any debris from the drilling. But.....

Originally Posted by Maltman

You don't want to remove roof lining - trust me

.... removing the roof liner seems like more trouble than I'd like to take. Maltman, what are the specific issues you've come across while removing/reinstalling the roof liner?

[Maltman]

Originally Posted by exo-shell

.... removing the roof liner seems like more trouble than I'd like to take. Maltman, what are the specific issues you've come across while removing/reinstalling the roof liner?

Expect 6 - 10 Hrs - minimum. You have to remove tons of covers, plastic stuff, stuff which likes to break. Finally you cant remove the lining completely from your car without removing your windscreen.

The idea to drill a pilot hole from inside is not bad, you´re right - but its not worth the work you have to do.