I am not great with cars so I may explain some of this wrong, let me know please. I have a 2003 Sentra GXE with about 17500 miles. I just bought it about 2 or 3 weeks ago. It has been running fine for me(until today).......Some things I have noticed before are some slightly funny smells coming thru my vents sometimes, once thought the exhaust smelled slightly wierd too, like it was too strong (not that i smell my exhaust but i was outside of the car when it was idling)..........Today, i pulled into my driveway as usual, put the car in park, engaged the parking brake as usual, left the engine running and got out to open my garage door(as usual)...when i got back in, car was still running.... disengaged parking brake, then I shifted it to drive, and it shut down(the lights came on that are usually on when car is in 'ON' but is not running, like service engine soon...etc....also i think it made some beeping noises, could be wrong.)....I think I had my foot into the gas slightly as I shifted, but it could have died first. It started up fine(alll lights went out (except seatbelt, but that was expected)), I put it in the garage, no noticable problems, except when I got out it was making an unusual noise....it had the normal pinging (the catalytic converter if i am not mistaken), but there was another sound, very similair, but much faster, almost like a liquid dripping somewhere....looked under the car, no noticable leakage of any sort...................(If i t helps I once noticed it making pinging noises while I was idling at a red traffic light, when I pressed the throttle the pinging got faster and then was too fast to hear it, so that likely is nothing, just seemed slightly unusual to me).............Please just need some idea of what is going on, this car is very new, and I have taken great care of it, although i didnt have it for its first 16000 miles.