He said so and it does seem to have solid axle and it only shows it driving on dirt and grass.
One way to solve it would be to have only single wheel powered. If you get that one powered wheel lifted you could shift your weight to tip entire vehicle (assuming you took care to load it evenly).
Or just use a limited slip diff. Allows some slip for cornering, but only, well, a LIMITED amount you don't end up with one wheel in the air spinning like mad and the one with traction not moving at all.
One way to solve it would be to have only single wheel powered. If you get that one powered wheel lifted you could shift your weight to tip entire vehicle (assuming you took care to load it evenly).