Hall, a veteran Lotus wrench, started with the 1966 Elan street car and turned it into a 26R that's arguably better than the factory original. Except for the engine block and head, original 26R body and Elan chassis, just about everything is custom built, highly modified or special order, from the fabricated oil pan, brake lines, safety wiring and oval exhaust tubing to the six-speed sequential transmission.
The episode is an unusually-long 21 minutes because, as an in-house build, Leno can go through the process of putting the whole roadster together. When he takes it for a drive and keeps going on about how it sings, you can hear it, too. It's worth the time to check out Mr. Hall's Opus in the video below.