Lease:
Something to consider: does the dealership take care of all maintenance free of charge during the lease term? It would be nice to not have to worry about actually keeping up with a car. I'm not sure if that's a thing just thought of that. Also might be the way to go if you want a really nice car, but in med school I would imagine most people, even car people, have "just a car."
Used Car:
Don't get me wrong I like Range Rovers, BMW's, Teslas and other expensive cars as much as the next guy but for now as a student, I'm very satisfied with a 13-year-old Honda Accord. I have had it for 3 years. It is a lot sharper than a lot of other cars that old. Very reliable, does the job of taking me to school, driving to the next city over, to the beach, New York, Florida, etc. and I never worry about it giving out. Only one thing has gone wrong (which may or may not have been related to hitting a tree, idk) and it was not expensive to replace which wouldn't have been the case with the other cars I like. I'll be honest that I lose track of time and don't take care of it like I should and I'm not sure that kind of neglect would fly with many other cars. It also wasn't too expensive and has everything (Leather heated seats, better radio than some of my friends, sun roof, etc.)
Some of the newer Accords are even nicer, I probably have another car or two to go through before I'm "set" and what I'll probably do is buy another (newer) accord. Really, I think they're great student cars.
Just don't put on ridiculous add-ons that make it look like a DIY douchemobile - Like what you see (hear) at Sheetz at 1AM. Not cool haha.
*So are civics though