today I get in my car, start it, put it into Drive (auto) and push the gas pedal, my engine revs but that car remains stationary, again, again, again... I try reverse, revs but again the car does not move... put the car back in park, turn off the car, start it again, and all is well, I put it in drive and drive home. what do you guys make of this, is it need for concern? should I make plans for a 5 speed swap?