i test drove a 05 x3 3.0 yesterday and loved it but on the second test drive the thing started to shake really bad at idle and then it started to bog when you accelerated. Got back to the dealership and shut it off and turned it back on and the service engine soon light came on. Dealer told me it was probably because its sat for a while but i dont know. Any one else ever encounter this and should i stay away, they said they would fix it by the time i picked it up but im a little worried about it. any suggestions would help.

Thank you