The blonde bought herself a new Mercedes. She could drive the car during the day, but at night the car wouldn't move at all. She tried driving the car at night for a week with no luck. Furious, she called the dealership, told them the problem and they sent a mechanic to the house. The mechanic gave the car a thorough inspection
and could not find anything wrong.

Eventually, he asked the blonde, " Are you sure you're using the right gears?"

"Of course I am. I'm not stupid. I use "D" during the day and "N" at night!"