Everytime my mom drives her Civic, when she parks and turn off the engine after a drive, the car tends to smell bad when we go outside.(Well, the engine smells bad)
I'm pretty sure the oil's fine because we've checked that already, so I have no idea why it's smelling bad.
The smell does not come up when she starts up the car in the morning, or when the car has been left for a few hours.
It only occurs right after she drives it to the store and stuff.

The bad smell worries my mom and me because we're afraid that it might break down in teh middle of the road or burn or something.
Any suggestions would be appreciated.