lift: it's just a fancier variant of the "parking lift", used by people who live in urban areas or inflicted with HOA parking rules.
trailer: I *like* that idea. And as a further variant, you could look at the "camping trailer" designs from the 1940s and 1950s. These were designed to track in the same width as the car, so they wouldn't hunt when going down rutted dirt roads to camp sites, and they were no taller than the trunk lid, so as not to obstruct rearward view. Most cars didn't have side mirrors then. They had slide-outs for cooking arrangements, and you either crawled inside to sleep or stored a tent inside.
Nowadays those trailers are basically nonexistent, replaced by the Coleman and Apache "pop-up" designs. They're a lot more convenient, but heavier than the old type and without as much storage.
I'd never thought of a trailer for a BOV, but it makes a heck of a lot of sense. And cheaper, too.
I couldn't find a picture of the kind of trailer I'm talking about, but the "teardrop" was a larger variant. The basic difference was that a teardrop was taller, with room to sit up inside, while the old style required you to crawl in; it assumed you were primarily going to sleep in a separate tent which it carried inside.