ok after my srt6 set for a little bit and i start it up for like 5-10 secs the car shakes almost like its misfiring, it only has 150 miles on it like i just got it lest then a week ago is this normal do other peoples do this, and do the all idle at like 300 rpms were that little line is on the tac?

 

it does have a very slight misfire kind of shake at idle for me as well... the 90 degree v6 has this inherently, the balance shafts help minimize the shake, but cannot completely take it away... change the oil if you haven't yet, bet that car sat on the lot for months and months like all of ours did 0w-40 mobil one synthetic only... remember...

 

Mine shakes a little also. It's inherent in the motor. At idle the supercharger is not engaged and the compression is 9 to 1. At high rpm you will be hard pressed to find a smoother motor. It's amazingly smooth.