I agree. Your first car needs to be a beater, just because bad things happen, and when you've been driving for less than a year, chances are that the insurance company will say the bad things were your fault.

My younger brother, with about a month's worth of driving experience, totaled my old car against a mountain and gave his ex g/f 21 stitches. RIP 86 Nissan Stanza station wagon (For reference, if a golf cart and a cardboard box had unnatural sex, that's what this car looked like, and although it leaked 3 different types of fluids, it was still my old car).

And use the money you save now to get something pimping once you hit 19. Trust me, it's worth it. (That's what I did )

Also, you learn some valuable driving skills on shitty cars, mostly like learning how to recognize the limits of your car and react to them instantaneously. There's a big advantage to learning what tire-slip feels like and how to correct it at 15MPH as opposed to 35MPH.