The DeSoto you know could've been something very different, as this concept art from Steve Purcell's blog reveals. The image is from Sam & Max Plunge Through Time, a never-released game first announced in 2001 as an Xbox exclusive.
The best part: Plunge Through Time was also being developed for PC, and in that version, the DeSoto's controls provided every key on the keyboard with a function, "however bizarre" that may sound. Is there a button that will resurrect this game? Because we totally want to push that button.