California Fever?
https://www.imdb.com/title/tt0078581/

I think this might be the vehicle you are talking about:
https://www.youtube.com/watch?v=xwSA0JGIoVM

Just made a page for it: https://imcdb.org/movie_78581-California-Fever.html
Edit: And I just noticed this is the same crazy vehicle that showed up in a recent movie: https://imcdb.org/vehicle.php?id=1285139