In the course of retrieving an orange that rolled underneath my new to me 2012 Cadillac SRX in the garage, I accidentally noticed a fairly significant dent/indentation in the center exhaust pipe that runs along side the drive shaft. Can't believe it's normal. No sign of any impact damage--it's been that way quite a while. Question is are there any negative consequences to this? Should I worry about it? Some reasons I am concerned about it are that the carfax showed 2 service "incidents" pertaining to driveability. I have noticed the engine shakes significantly at idle when in park--it's not too bad when in drive but I do sometimes notice a slight shake. Also, the car pings or diesels more than I think a 35,000 mile Cadillac should. Could all these consequences be explained by the dent in the exhaust pipe? Could that be causing excessive back pressure resulting in those symptoms? Have a service appointment later this week for some other issues and am wondering how hard to push this issue? I really do need some good advice here. Thanks in advance.