Twin Mill is a twin-engined prototype concept car originally designed by Ira Gilford for the 1969 Hot Wheels lineup. It is recognized as Hot Wheels's first original design, done from the ground up at Mattel with no external input. It features a doorless canopy design, with entry and egress done through an opening canopy up top, as well as two large big block engines. Today, Twin Mill is a highly popular model and is often considered the most iconic Hot Wheels model, alongside other models like Bone Shaker.To capitalize on the model's popularity, Mattel commissioned famed hot rod builder Boyd Coddington and his company, Hot Rods by Boyd, to create a life-sized version of the Twin Mill in 1998, with Chip Foose overseeing the project. Hot Rods by Boyd however went bankrupt later that year; at the time the project was unfinished. The project remained unfinished until Carson Lev decided to revive the project, commissioning hot rod builders Barry Lobeck and Carron Custom Industries to finish it, with the completed car making its debut at the 2001 SEMA Show.The fully-functioning Twin Mill is fitted with two 502 ci (8.2L) Chevrolet big block V8s with superchargers, with the car stated to be capable of some 1400 horsepower. Entry and egress is done through the opening canopy. The car uses a GM TH400 3-speed automatic transmission. A second replica of the Twin Mill done to the same specifications as the original was recreated by Action Vehicle Engineering, painted in blue. Now part of the Garage of Legends, Twin Mill makes frequent appearances at large events organized by Mattel, such as the Legends Tour. It is currently painted in a Mobil 1 paintscheme.