A woman brought her car to a mechanic complaining that it sometimes wouldn't drive well, had gotten very sluggish, and was using alot of fuel.
The mechanic looked opened the bonnet and looked around the engine bay for a while, when he returned to the woman he said to her;
"I know what's wrong with your car, it's pregnant!"
The woman laughed and asked how could her car be pregnant, the mechanic told her
"well, it was fucked long before it got here!"