Leaking oil that collects under a car when it is parked overnight may signal engine problems that can get serious if neglected. Car owners who want their car to be in top condition at all times can find out where the oil is coming from by observing its color and smell. Cars run on oil and when a huge amount leaks, the car might stall in the middle of a busy road, causing traffic congestion that can be annoying to everyone on the road. more