/soapbox
I guess my point is this: most of us have to choose between future wealth or a full lifetime of indentured service to an employer ... a bet that's getting more risky, and one that might look great at 30 but not so great at 45.
20 years ago it was common to know someone who worked for a company for 30 or 40 years ... now those people have all retired. The 1950s and 60s created a culture of (deserved) certainty: if you played by the rules (and many times even if you didn't) you were more/less guaranteed a steady job for life, which mean a steady income, which meant you could confidently fund your life.
That model is almost fully collapsed.
At 30, many people view promotions and salary increases as inevitable and they extrapolate out, seeing their incomes forever rising. That means they see little risk and plenty of time to save later. That thinking has two major flaws:
(1.) If you don't save today, you voluntarily give up harnessing the most powerful force in the universe: compound interest. And once spurned, it can never be recovered. i.e., every dollar you don't save today punches you in the nuts 30 years from now.
(2.) Many 45 year olds discover that their big salaries are suddenly at risk as they see their peers take a lay off or their company fold. And they never recover from that financially. This process is aligned to business cycles: things that are unsustainable tend to not sustain. A big money job at 45 is pretty hard to find compared to good money job at 35.
It's for those reasons NOBODY at 45 thinks "gee I'm sure glad I bought that M3 at 30" because they realize the true price was comfort for the rest of their life.
I've watched whole teams and some businesses burn down because a 40ish person had a meeting with their financial advisor, realized how fucked they were, and decided to go apeshit for any dollar they could get any where.
/endSoapbox
(a.) no I didn't forget about having a car - some people buy a beater and wrench it. Some people live in the city and never buy a car. some people just use Lyft.
(b.) Another way to look at it is to create an M-car fund. E.g., If you save $186,000 assuming a 5% return, that'll give you a $1000 M-car payment for 30 years. To save that $186,000, if you put away $2000/month at 5% annual interest, it'll take you roughly 6.5 years to get that principle. Just rough math, but the point is, sweating for 6 years gets you an M-car for 30 years. Not a bad deal.
This is where my "afford" point comes from. I want to be financially independent at 50 with the same lifestyle I have today (which means I can work or not and if I do, I don't need the pay). That means to "afford" an M-car today I have to be able to fund it outside of that like
trey100 said. Thus if you don't have enough in the bank when you fund your m-car your retirement lifestyle is going to take a huge hit ... and if you have healthcare costs on top of that (or kids) you're doubly fucked.
(c.) Mr. Money Mustache will explain how you can retire young on a normal income through the use of BadAssity. And there's a zillion other blogs of people who've done the same. It ain't that tough, and it's not that much of a sacrifice. If it is, you're a spoiled pussy.
Very good post.
- but the math is the math ... and it's the Warren Buffet way; he's not afraid to give away all of his secrets because nobody will follow them. 
