Ok, I got my 8 last light, brand new, has the M flash. while the tac needle doesn't jump aound like its idling rough, I can feel some vibration from the engine at a stop in my seat. Is that normal? Bear in mind this is my first RWD car, so I'm not use to a drive shaft running the length of my car. Thanks

Oh, I love the car :)

This "lope" at idle is normal for M-Flashed 8's.