I bought my first N54, a 2007 335i coupe 6MT Jet Black/Saddle with 30k miles (1 owner euro delivery car that was 100% stock) in 2012 when I was 20 and in college. I did high end car detailing on the side for years during high school and college and was able to pay cash for it. It was modified to be FBO and ran e85 along with a slew of suspension/drivetrain components. Not too much aesthetically. Drove it until 2015 when someone rear ended me in it. Didn't total it but I sold it off when I moved to NY after school.
Drove a 2013 Audi S4 for a while after that and now I just bought my second N54 at 25 years old a couple weeks ago. 2009 335i Sedan 6MT Jet Black/Black. 44k miles, 1 owner, 100% stock (for now).
This new one will be much more of a build than the last one. I was also at school for Engineering.