While I'm not a BMW owner, I'm only a few years older than you and I agree with a few others, get a cheaper car as you are only 16. Get something inexpensive (used, at the prices you have pointed out) and use that as your primary car until you are a more experienced driver OR until you finish college. Personally, I was about to buy a new car about a year ago but a change in education brought me into Philadelphia and there was no need for me to turn in my 96 Oldsmobile. The car still runs great when I drive it when I am in New Jersey visiting friends and family.
Bottle lime: save your money for more important things (food, gas, insurance, fun, etc...) and get a cheaper car which won't hurt your pocket when filling up at the pump. Go with an older Honda or Toyota, I'm sure you won't be disappointed with either. 😱