i have a 2004 cavalier and for some reason the speedometer just stopped working, any ideas what it could be? The dealer says a rough estimate is about 300 dollars but they're not even sure what it might be, they say it could cost more. And also my ac now only pushes out hot air. Mechanic says it could cost anywhere from 100 dollars to 900 dollars to fix!! I need help does anyone know what might be wrong with my car?

Speedometer could be a number of things but the cluster is probably bad. You can get another 00-05 cluster from a junkyard for $50.

You could just be low on freon, in which case it shouldn't cost too much to add more. You could also have a leak like I did at my compressor which could get very costly if you don't know someone.

it happens.
hit the dash once or twice. fixed mine. lol