Strange Bump Feel
 

not sure where to put this but before I bring it to the dealer I thought id as as maybe somone has had this happen. I have a 2011 JK Unlimited still under warranty. About a month ago I was in an accident where somone pulled out in front of me and I hit them. No air bags, minor alignment and new bumper, hood, quarter, fender, grill. Rad etc was all ok. Got it back and all was good. How ever one day I noticed that when I stoped I felt a bump as if somone had just kissed me from behind. I looked in the rear mirror and no one was close enough to have hit me. So im like ok weird. So ever know and then when I stop depending on how I stop I feel this bump as if somthing is slideing into my jeep and tapping it from behind. I wonder if its somthing in my tranny or drive shafts? Becuase when this also happens the jeep idles a little rouger it seems. I can put it in Nuetral and its ok.

other wise it drives good and shifts good, reverse is fine other then it feels it idles a little rougher in reverse now.