That's how I started my truck camping. But one year I visited Yellowstone during a particularly nasty heat wave and the black flies were borderline life threatening. I remember pulling off at one lookout and in seconds there were hundreds of flies on the windows. If you stepped outside, any patch of skin that didn't have insect repellent applied would be found in seconds and these were the flies that drew blood. My only sanctuary was the drivers seat of the truck or crawling under the cap. That was when I decided next time I made a trip like that I was going to have someplace I could go when being outside was a less than attractive option.
Panther Campers makes some small no-frills models that would be a step up from the cap but not all the way to a full self contained TC. I decided I also wanted to have a shower with me, so...
