Electrical problem, I think
 

My check engine light came on and lately when Im driving the speedometer will freak out. If Im slowing down like at 50 it will drop down to ten instantly, sometimes even if Im coasting down a hill off the gas. Once in a while if it stays low long enough my car will shift and the radio will get a bit quieter. Im not sure what to say because the volt meter stays fine when it happens. Any idea?

bad wheel speed sensor prob... the radio has speed compensation, so it gets louder when you're faster. If the sensor was bad it would throw a code too...

take it to autozone and get it scanned and post up the code you get.

Thanks, Ill try it, but I probably wont have time till next weekend.