My car vibrates

My car was at a collision shop for almost a month. While it was there, it was hit by another car! The front end was hit. The day after I brought it home, the battery died and I needed AAA to come out and replace it. Then, as I was backing out of the driveway, my car started to shake like crazy! I called AAA back and asked if they guy could come back to see if the battery was put in wrong or something. So, they sent a tow truck! The guy got in my car, started it up and the shaking was no longer happeneing. I felt like an idiot. After he left I got in the car, started up up and backed out of the driveway and the shaking starting again! And it continued as I drove around and then it subsided. What could this be?

If its coming from the engine, it may be that after a dead battery, the computer just needs to relearn the fuel mixture settings.