A modification that adds wider fenders to a vehicle, accommodating wider wheels and tires than the original body would allow.
Widebody describes a vehicle modified with significantly wider fenders than the stock bodywork. The purpose is to accommodate wider wheels and tires for performance or styling reasons. Widebody kits range from bolt-on flares (often urethane or fiberglass parts that attach to the original fenders) to full hand-built fender modifications (cut and welded steel or aluminum, like RWB).
Widebody kits originated in motorsport. Group 5 racing in the 1970s and the original Porsche 911 Turbo Carrera (the famous "whale tail and flares") established the visual language. Modern widebody kits are influenced by both that motorsport heritage and Japanese tuner culture (RWB, Liberty Walk, Rocket Bunny).
The most famous modern widebody kit makers include Liberty Walk (Japanese, started by Wataru Kato), Rocket Bunny / Pandem (Japanese, by Kei Miura), and Rauh-Welt Begriff (covered separately). The aesthetic typically pairs widebody flares with deep-dish wheels, aggressive ride heights, and bold liveries.