MINI transmission problems? :(

I have a 2006 MINI- red, manual, nicknamed Sgt. Pepper, totally awesome. Two questions:



First:

Sarge is having some troubles lately since it got rear-ended by a knucklehead on July 4th. The damages seemed relatively superficial at first. Well, so I got the bumper all fixed up just fine. But since getting it back from the shop, I’ve noticed a kind of high-pitched whirring sound–above the usual transmission and engine sounds-- when I’m in low gears (1st and 2nd) and in reverse as well. I honestly don’t remember hearing that sound before the accident, and my boyfriend noticed it as well, but Does anyone know whether it’s possible for a rearender to cause damage to the transmission? And if so, what might be the cause of that sound?



Second question: I’ve noticed, since I bought the car last fall actually, that the engine sometimes falters when I try starting the car, as if it were a really old clunker or something. But it’s not, it’s a brand new car! Has anyone else had this experience, and what do you suggest is the problem and how to handle it?



Thanks!! Love car talk!!