A slot car (sometimes, slotcar) is a powere miniature auto or other vehicle which is guided by a groove or slot in the track on which it runs. A pin or blade extends from the bottom of the car into the slot. Though some slot cars are used to model highway traffic on scenic layouts, the great majority are used in the competitive hobby of slot car racing or slot racing. Slot cars are usually models of actual automobiles, though some have bodies purpose-designed for miniature racing. Most enthusiasts use commercially-available slot cars (often modified for better performance), others motorize static models, and some "scratch-build," creating their own mechanisms and bodies from basic parts and materials.