The host of the Moon Rover contest (ColourSchemer on Classic-Space) suggested using brick-built wheels. I haven't done much of that before, but I immediately thought of using the plate with an octagon of bars around it as the hub of a wheel, and found that I had enough gray skis to surround two of the hubs. After a little experimentation with other parts, I had my (front) wheels. Hopefully I'm not unconsciously copying the design from something I've seen before.
I didn't take any photos with plates for reference, but the total length is exactly 16 studs (the limit for the contest). I originally started to build articulated "arms" that would have extended the front wheels, but luckily I checked the limit before I got too far with those.
The black thing between the front wheels moves up and down and has two electronic eyes. It's basically a little robotic head, which allow the rover to pilot itself when the need arises. Hence the name SmartRover.
The control panel is on a hinge and has enough room to tilt slightly. This makes it easier to position the control sticks in the hands of the driver minifig. She has a lot of room to slide around until the control sticks anchor her in place. (You can see her holding them in the first overhead photo).