I drove a Honda Accord through med school. Parents paid for car insurance, but everything else was on me via student loans. I did residency and fellowship, so it was a long time before I could afford anything decent. I finally bought a 335i 5 years after going into private practice and only just recently traded it in for M3.
I agree with others who say reimbursements keep going down every year. If you throw in having to pay overhead, staff, their health insurance etc, then you make even less. I now work for a healthcare firm and got out of private practice due to burn out and dwindling reimbursements. I tell people who ask me if I'd go into medicine again if I had a choice, and my answer is always no. I am sure a lot of people will still point out that doctors' salaries are still good; however, if you factor in the loans and years to get a return on your investment, then it's a big negative return for years.
On a different note, I love my M3!!!