Garage (Luigi's Mansion: Dark Moon)
From the Super Mario Wiki
The Garage is a room located in the Gloomy Manor, in Luigi's Mansion: Dark Moon. This room can be seen from the outside, where two Greenies are spotted playing around with the car. One of them seems to be doing something inside the motor, and comes out holding a bulb, which is later revealed to be the Strobulb. They will then exit the room holding the green bulb. In the first mission of Gloomy Manor, there is a Boo hidden in the upper right hand corner of this room. There are some windows to look out of, a blocked off garage door on the left, and a few tool chests around. During the credits, E. Gadd, Luigi, and a Slammer are seen riding the old Automobile.
In the fourth mission, Luigi can spawn a Gold Greenie by opening the chest at the left of the room and then trying to exit.