T3man, yeah in power mode it is ok
fUSiON, the vibration only lasts a second at most and seems to happen as the gearbox decides what gear it should be in.
I'm starting to wonder if it is simply because the computers running everything have the car in a different 'mode' as you kick it in the guts, but then the sudden change in engine requirements might be causing the engine to run rough.
then again I don't know much about engines, I'm just a reformed nerd

I could be wrong...