I still remember when I was in a similar situation as you when I was your age.
Here is the car I lusted for (and still do actually):
Back on topic: I studied biology before switching over to engineering. About 25% of the class in first year said they wanted to go to med school (class size of ~600?). After third year, one guy I knew got into med school (McMaster), then another two got in after finishing their undergrad (one continued at University of Toronto, second guy went to the Caribbean's). Of course I didn't know everyone in the class but I would imagine <2.5% make it to med school, then who knows how many actually graduate. Some peeps went to pharmacy school, some did their masters and few completed their PhDs.
Not trying to rain on your parade - maybe you're part of that small percentage who will end up in med school and graduate.
Personally, I would hold off until school is over.
Good luck and WORK HARD!