Planet Hot Wheels was a massively multiplayer online racing game created by Hot Wheels' developers and Mattel, Hot Wheels' parent company. However, in 2004, after displaying a message on the site for nearly a year that Planet Hot Wheels would be back soon, Hot Wheels permanently removed the game from the website with no warning issued to its players. Many Hot Wheels fans played the game and speculations have been made on why the game was removed, but Mattel has not made any official statements.

Many players enjoyed the virtual racing game because of the Highway 35 story features and because of its use of real world Hot Wheels' models and the ability to upgrade their cars with decals, paint jobs, weapons, and other assorted components. To get these parts players could buy specially marked Hot Wheels cars and enter a code to get an item. Users could also race and play mini-games to earn credits, the currency of Planet Hot Wheels, and purchase items with them.