Transits have plenty of room in there, I know a few people on here use Chevy HHR Panel's. I think the bigger question is what do you need to fit inside the vehicle? I'm a mobile detailer but I'm eco, so no water tank, and no generator. I'm (seriously lol) looking at a 2016 Smart Car for my detailing rig. But you're asking if a Transit's big enough, it would have a ton of room. They're pretty damn big inside, way bigger than they look from the outside imho. And they're tailored to be a word vehicle so you don't have to mess with taking out seats and stuff. I'm also considering a Transit Connect.