RVs
'(<a href="http://www.j-archive.com/media/2010-12-07_J_26.jpg" target="_blank">Jimmy of the Clue Crew reports from the RV/MH Hall of Fame in Elkhart, IN.</a>)  The GMC Motorhome from the '60s & 70s was among the first models to have this innovation that helps with traction by putting the weight over the <a href="http://www.j-archive.com/media/2010-12-07_J_26a.jpg" target="_blank">wheels</a> that do the work'
front-wheel drive