The Actor Trailer is a prop introduced in The Sims 3: Late Night, and is unlocked when a Sim reaches Level 10 of the Acting branch of the Film career. It is a rabbit hole, and Sims can sleep in it. Sims can even WooHoo in it, though they may get caught by the paparazzi.
The Actor Trailer can be placed on a Sim's home lot. Like gifts that are received from work and other Sims, it is usually placed in the Family Inventory.