2002 Nissan Sentra Rumbles over 55m/hr

So my car has been the unfortunate victim of several hit-and-runs. I thought all the damage was superficial, but I'm not sure anymore. For the last few months, my car has started to rumble when I accelerate over 55m/hr. It gets worse the faster I go. Might it be the wheel alignment or perhaps a slight bend in one of the axles?

Sorry, I know very very little about cars. Any thoughts?

Thanks so much.

Greg.