OP, you're right, a new M3 would be $60k plus. Most coupes are purchased with all of the "bells and whistles". Therefore pushing the MSRP to $72-75k. Do you need to have a good level of income or savings to buy a new M3, yes. But that is not the complete picture. How much of the income is being allocated to other obligations. There are plenty of people in different career paths that can make $80k, 90k, 100k plus and afford a M3. However, add-in the mortgage, investments, and other required financial commitments, some, even with a good salary, can not afford a M3 (or similar priced vehicle). Also some that can, opt not to pay the new price. Rather go with a 2-3 year old model. Financially speaking, this is the smart path. Let someone else take the depreciation.
The question, while I understand why you are asking it, is often posted on different forums. Backgrounds range from engineers to doctors, military to business owners and sales to Walmart (yep, seen that one a few times).
My background, automation and controls (i.e. engineering) and a small consulting business on the side.