Vibrations felt in the steering wheel. Steering also shaky.

I have an 2007 Acura TSX(2.4L I4 - auto trans) with 6000 miles on it. The car was running perfectly. At 5000 miles approximately, it was rear-ended by a Camry while it was in drive but at a complete stop. The accident damaged the rear suspension, exhaust system and the floor of the trunk. Except for a few creaks and and groans from the suspension, the car drove flawlessly for 400miles till I got it repaired at the dealership. As part of repairs, half of the exhaust system was changed as was the cross member of the rear suspension A wheel alignment was done too. Ever since the repairs, the steering wheel feels heavy and shaky. I can feel vibrations through it almost all the time. The car also shakes much more when idle. I got an alignment done on it again, but that didnt help. The steering wheel doesnt feel smooth, and feels as if its rubbing against something that it shouldnt be. Also at times I hear a groaning( regurgitating steel girdle sort) noise when I turn my steering wheel.
I got it checked twice at the dealership but they cant find anything wrong with the car, and feel its behaving perfectly fine. However, I hate the current feel of the car, and while driving I no longer feel in control of the car. The vibrations in the steering wheel are spoiling the entire experience of driving a luxury car. Since my car is hardly 8 months old, I dont know wht/who to blame. Also, my rear michelin tyre has developed a crack in the sidewall for absolutely no apparent reason. What could have caused this? And is such a thing covered under warranty? The dealership said no.

Could the accident have cause any of these problems, and if yes, then why did the car drive perfectly fine till I got it repaired. Please help. I am highly desperate for any solution.


About the groaning noise, it was happening more last month, but ever since it became cold it has become more seldom. Dont know whether this is just a coincidene?

The hardness in the steering wheel has also reduced ever since the repairs in the last few months. It was verrry verry hard and heavy when the car got repaired in august. But now it is much lighter compared to that, but still heavier compared to pre-repair state.