I drove a number of really old Ford Fiestas, the first of which only had 4 forward gears but a speedo that (rather optimistically) went up to 140
Basically, my insurance cost so much that no matter what I never had anything to spend on a car. So I bought fiestas for about £500 a pop, drove them for a year each, then stripped anything that was in good shape and bought another one. Having a full set of spare wheels came in handy a few times, and spare exhausts/carbs too.
Tbh as long as its reliable then you can't go wrong with an old car for your first one. It gets you in the habit of driving the limit and not taking risks overtaking and what not. Also, lacking power steering makes you learn to maneuver a lot better.
I'd suggest you get yourself an FM tranciever for you iPod/whatever btw, and keep whatever old ass stereo is in there already. Someone sees even cheap decent modern stereo in a beat up old car, it'll end up stolen. FM tranciever means it'll work with any radio and you take all the expensive stuff with you.
Oh and when you do get a nice car in a few years time, you 'll really appreciate having power steering and AC and all that jazz. If you start out with all the mod cons then you don't even notice they are there.