Street parking in DC is a
HUGE headache. Basicly, DC is financed by their traffic violations so they have made getting a street permit a hassle, in Georgetown's zone only cars with DC plates can get a permit, getting that permit and plate will take you at least 2 full days of quality time at the DMV. Then there is the fact that only DC residents can get DC plates so that you have to change your residency (which obviously is going to affect your application to your state schools, not to mention taxes and insurence which your parents wont be able to cover on their plan if you change your residency.) It is really not worth the hassle, everyone I know in the program living in Georgetown misses having a car but are able to function quite well without one.
Personally I wanted a car in order to go grocery shopping in Alexandria (cheaper then Arlington and much cheaper then DC,) go to church, and have the ablity to skip town everyonce in a while (most of the time to Williamsburg and Busch Gardens, my guilty pleasure
) but its by no means a necisisity in DC, home to this country's best public transportation system (which conviently serves DC and all its surounding areas with the exception of Georgetown.)
If you really want a car but want to be close to campus, I strongly suggest Rosslyn. Georgetown is 2 city blocks away from the river and Rosslyn is directly across the river from Georgetown, when the shuttle bus isnt running its a 30 min walk to/20 min walk back (due to a hill) from the Metro stop to the medical campus, which isnt bad at all.