A hot rod lover from California looking for his first rat rod challenges Steve to transform a 1931 Ford Model A into a salt flats racing machine. Turning this pile of junk into a Welderup special will take every ounce of Steve's talent - and getting it done before his client returns to Vegas will take a miracle.

Steve digs back into his Montana roots to build his cowboy buddy J.R. the ultimate ranch truck by Frankensteining together a pair of vintage Dodges. Already struggling to get the truck done on J.R.'s ridiculous budget, Steve has to scramble to track down a vintage mini-bike for another client.

When client Jonathan Mill brings Steve a 1928 Buick filled with rotten wood his excitement at rat rodding an original 'gangster' car soon fades when he learns his client wants it to be an electric car. The creator of the award winning electronic emergency brake, the E-Stopp, wants the car to promote his company at SEMA, the largest car show in the world.

Guns and gators are on the menu when a Texan house mover brings Steve his family treasure: a 1938 Big Rig Mack Truck cab. Stuck with a cab one step from the grave, the crew has its work cut out for them and when Steve blows out the engine on Welderup's signature car, the D-Rod, his head's not in the game.

Steve trades in his trademark rust for a shiny paint job when he tackles a 1965 Lincoln Continental for a flashy bartender from L.A. Adding bling to a car that his whole crew hates isn't the only thing Steve has to worry about: his two sons are in town and showing they don't fall far from the tree by tearing the shop apart to build a "rat quad" go-kart.

Steve yanks a '49 Ford F1 out of a farmer's field and battles to transform it into an eye-popping promotional vehicle for a couple of his dad's old friends. Tensions mount with the Welderup crew as shop upholsterer Barber acts out after Steve outsources his job and money guy Dave's mistakes begin to pile up.