I have a 2006 Pontiac Grand Prix GT Supercharge when I press the gas it bounces all over the place but once I let go f the gas it feels OK. I took to a shop they said it needed the hubs replaced, so we replaced them but the problem didn't go away. Can anybody help me? Does anybody know what is causing this?

define bounces all over the place? Sounds like could be CV axles. Check them for play up and down. In and out should have movement at the inner most joint but nowhere else. Up and down should have no wiggle room. Casues vibration on acceleration. Cant believe a shop would do the hubs and not check CV axles tho. Hubs casue a grinding noise when they wear out.

It shakes as if there is a ball on one of the tires or it's way out of alignment, but it's not. The weird thing is it only does this when I accelerate. Thanks for your input..

yea I'd bet on the C_V joints too ... you know you have to replace them both .... then realign the front end ...

Thanks guys I'll have it checked into & give u an update. I just need to get this fixed...

or needs new engine and tranny mounts . might be that if you give it gas it might go so far outa alignment that is giving you a death wobble same thing happens to police interceptor impalas