When the world of custom vehicles and performance vehicles collide, you get a pretty awesome mix of form and function. Not only do they look good rolling, but they can make the rolling function fun.

Diesel exhaust fluid (DEF) is nothing new. GM’s Duramax-powered Chevrolet Silverado and GMC Sierra 2500HD and 3500HD pickups have had used the stuff since 2011. So has Ford’s F-Series Super Duty.