If you have the means, I say go for it. But that means cash for school and the car. Don't take a loan for school and the car, otherwise that M3 will cost you the same amount as a Ferrari at the end of the day.
I went to medschool with a Honda Prelude VTEC. Fun car, perfect for me. When I found I had a one year internship before moving to NYC for residency, I bought an E36 M3 (6 years old at that time and well into the E46 model cycle). Great car, lots of fun, cheap to maintain, and sold it after a year for a profit! I bought another one straight out of fellowship, again used it for a year, and then sold for a profit.
I bought my E90, only after establishing a job, creating a solid rainy day savings fund, and receiving a sizable bonus.
And you know what--the delayed gratification made it that much sweeter!!
For the person wanting to do anesthesia--I'm curious too, what makes you want to do it? I am an Anesthesiologist/Pain Medicine doc.
08 E90 M3 Interlagos Blue
99 E36 M3 Cosmos, #2--Sold
99 E36 M3 Cosmos, #1--Sold