I'm 22 (almost 23) and just bought an 08 335i. Pretty simple - I worked for it.
Had a job since I was 14, graduated college w/ a diploma in Computer Engineering at 21. I've been programming since I was 16, so I landed a 60k/year job. Some hard work and that's up to 70. I also have my own business which nets me ~25k a year.
With some hard work its really not that hard. I've lived on my own since I was 18 and have student debt as well.
But really - who gives a shit?