Easwaiting at a red light today and the car started shaking rather violently. As I was waiting I shifted into neutral to blip the throttle, hoping it would snap out of it, but the tach wouldn't make it past 1000 RPM. I was able, very slowly, to he into the parking lot where I was turning. After coming out, it started up and everything worked as it should. The car is an SRT with 32000 miles. What gives?