08 chargers

i've owned 2 chargers now an 06 and an08. both 3.5 auto. the first one was an auto stick, and it really was apain in the a#&. the 08 is an auto without the slap . as far asmotor goes they run great, but the trans is a little sketchy on the big road. if the cruise is set at 70 and you start down a hill it will downshift out of OD and it hits pretty hard. the factory cant seem to find a prob though.