I've got the car, but I notice that the Fuel Cell Regulator is in my inventory. Wasn't it supposed to be installed by Smitty, or is it just some kind of bug that its still in my inventory?
Thanks.

There is a ghoul who makes clear that while Smitty thought it was the fuel regulator that was broken, it was actually the battery.
IIRC, you can go back to Smitty (or the ghoul maybe) to install it, and it will cut the car's fuel consumtion in half.

Hmmm...can someone elaborate on who/where this ghoul is?

In Gecko, north map.