That's just it, you see. The concept is what's good. Part of the problem of the link about BugMiniHomes is that they were created in the 70's. The passage of time has changed perceptions of what looks appropriate or good. Of course those look white trash; those harder angles and color schemes have come to be seen as such. To graft a seventies style trailer into a modern looking Scion would look unseemly.
But if you were able to design is such to where it functioned as a miniature home on wheels while keeping the general aesthetic of the xB, it could be all win.