ok so heres the problem. 2000 pontiac sunfire automatic transmission driving last night. We were driving fine and tryin to work cruise. Pushing pedal down not very agressively rpms went to about 4-5 ad then we heard like a ping and the car stopped accelerating and just revved. makes odd clicking/ grinding noise in reverse. wont move in any gear. 80000 mis and has accelerated on its own before, also very very slow to accelerate. I have a 1995 honda civic driven way harder with 200000 miles and it has never had a transmission problem. This car has been babied and shouldnt be breaking down like this. What couldve happened to it?