i ran in the ditch one rainy night and since then my 2008 pointaic gran prix want to let the rear end come around in a curve and it is really bad when the road is wet what could be wrong
Get the car into an alignment shop.
Maybe you also need new tires.
or a suspension component is broken or bent. Is there uneven tire wear?
Ken has the right answer. You've seriously damaged/bent something and it sounds like the car has become unsafe. Might want to call your insurance company too while you're at it. You're not going to like the repair estimate.
Looking for a Used Grand Prix in your area?
CarGurus has 2,641 nationwide Grand Prix listings starting at $950.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts