I'm turning 16 and working all summer to come up with a few grand to buy my first car, have loved cars my entire life and have wanted to drive one since i was 5. I'm not sure what i want to get as my first car that would be in my price range, i want something 2 door, if it isn't 2 door thats fine but it has to look sporty, like a Subaru imprezza, if you could just throw out some ideas to help me, that would be greatly appreciated it also should be something that can be upgraded because whatever i get i am keeping and making able to go a good speed, I also want to get into racing and drifting after i get driving experience, i plan on hitting the track next year so something that can be upgraded is a must.Thanks in advance for the help and advice and have a wonderful day.  

240sx - good for drifting its RWD
CRX - Just plain awesome  

A 240sx is what you want, there are other good first cars but the 240 is:
-RWD
-Not to powerful (good to learn on)
-Huge aftermarket support
-Easy to learn on
-Can become powerful

It'll take some time to find one under 4 grand that hasn't been beaten to hell. If drifting isn't to important to you a FWD hatchback would make a good first car (Eclipse, Civic, Golf). There are AWD eclipses but those might be out of the 4 grand range.