I know I'm not answering your question right now but I feel like I really need to say this so that you don't suffer the way I did. I seriously don't mean to derail your thread I just know first hand what will happen with that setup.
I had the MP HAS on my M4CS. Do not waste your money if you plan on kicking some ass on the track. You may think that right now you're a novice driver and you'll take it easy for a few years but that's highly unlikely considering how driver friendly the F8x is at the limit and how much you'll love doing it. The spring rates on the HAS are no more useful than the stock springs. At the very least you will be 1000000000000x better off with a single adjustable kit.
SYT_Shadow speaks highly of MCS and so does Bimmerworld but I never got a chance to put a good suspension to give you my honest opinion.
With a good alignment (probably even with the stock alignment), you'll notice that the car has an extreme oversteer bias - not understeer. You need to tackle that before you add more downforce to the front of the car but before you add downforce to the car, you need to stiffen the suspension. There's too much travel on the HAS/Stock springs.
See below for what MP HAS with Toyo RRs looks like and how much roll/movement in the suspension you will see. I'm avoiding curbing as much as possible because of how much it unsettles the car. I'm the gray M4 in front of camera car.
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