So here's a quite silly idea that I don't quite have the skill level to pull off. It's a solid joke, though.

Things I learned from this, and that I would hope to take advantage of if I do this again? The most important thing is don't try making the car realistic. This would read much better if it were one of those open-top sausage-shaped cars that toons drive in 30s cartoons and 50s funny-animal comics. Fewer fiddly lines demanding my, and the viewer's, attention and pulling away from the joke. Now, kangaroo is the right species to cast in this role; they're nice and distinctive, make sense sitting up like this, and it's easy to draw feet that don't look anything like hands. Also, I need to develop a foot fetish or something because I haven't put enough definition into the feet. This would probably also read better with a more cartoony kangaroo, something closer to Spunky's shape. Again, it would be less difficult to read, and easier to fit feet onto the ends of arms like that. And it would fit a more cartoony car better.

I'm not promising I'll do this one again with what I've learned, but I do feel like I have a better idea than this came out being.