I took this car to the dealership on 12/26/03. They told me it was the ERG valve and some switch in the transmission not engaging or something. Anyway, charged me $1200+, I picked it up on 12/31/03.... still had the same problem. Took it back immediately (same day). It has now been there for 6 weeks and is still not fixed. Does anyone have a clue? They are telling me they've replaced the fuel injectors, the harmonic balancer, repositioned the motor, changed the plugs, etc. The car drives great until you hit @ 52mph and then it has what someone told me was a chatter. I describe it as if you were shivering from the cold.