Vintage Hot Wheels Porcelain Sign. For sale is a Hot Wheels porcelain sign featuring Batman and Robin advertising die cast cars. Measuring at 11 3/4, this sign is the perfect size to display in your garage or man cave. The Hot Wheels brand is well-known for producing quality toys and this gas porcelain sign is no exception. This sign will enhance your mancave, collection, shop, or garage. It is your chance to own a piece of Hot Wheels advertising. Vintage Hot Wheels porcelain sign. 11 3/4 inches in diameter. Vibrant colors and excellent porcelain.