hello all, I am new to the forums. I just recently purchased a dream car of mine, a 2015 RT dodge challenger. I have been in love with the car since seeing the movie vanishing point as a little boy, so I'm very pleased with my purchase. However, I do have a small issue. I have never driven a A8 automatic transmission I don't know if this is normal or not or what's really causing this issue. but when I am holding speed in any gear, I stay around 55 or 60 most of the time, the car feels like there is a shutter. But when I step on the gas it goes away, however when I go back to holding the pedal to keep it at one speed it starts back and like I said this does it at any speed when holding it. So I am wondering if anyone here has has the same issue and what was causing it. It is not noticeable in sports mode but it is in regular driving mode. Sorry for the long post and thanks for any advice!