I drive a Mercedes 2000 c240 and my friend sitting in the passenger seat abruptly shifted the gears from 1 to 4 while i was going at 20 mph and 4 to 1 when i was driving on the freeway at 70 mph. My car is automatic however the car would vroom loudly afterwards and then stopped changing gears a day later. Did he damage the transmission and should he pay for a new transmission? my car now does not shift past 1st gear and runs loudly.