The 1973 GMC Motorhome was—and still is—a sight on the road today. This groundbreaking RV was just as interesting as its sleek body, with a V8 powering the front wheels and a spectacularly 1970s interior. And because it was the early ’70s, we had a different notion of what was okay to spray into the atmosphere as you drive. Like sewage, which an obscure option allowed this GMC to do.