I have an 06 Chevy Cobalt 2.4l with 380,000 miles on the original engine (though I had to replace the auto tranny at 300,000.) To say its held up well is an understatement. For about 50,000 of these miles its pulled my XLE Aliner hardsided pup-up camper. If considering a pop-up, I would only consider hard sides, not cloth for FT living,, as they are much better at keeping the weather and critters out. You'd freeze to death in a cloth sided camper but stay toasty warm with a tiny heater in a well insulated Aliner. They are expensive new, so I'd recommend finding a good used one like I did. Mine is a medium sized model with all the bells and whistles, but it's about all my little 4 cyl car can tow. For one person you could go a little smaller, but the model I chose has a cassette toilet/shower stall, refrigerator/freezer that runs on propane, 110v and 12v power, a couch and dinette that makes into a king sized bed (we leave it made out), microwave, 3 burner stove, air conditioner, etc. which makes it more suitable for extended living. Hot showers are great, but it only has a limited tank capacity (10 gallon fresh water and 6 gallons in the water heater) so if not hooked up to a water hose you must refill the water every couple days if showering. We use a couple blue totes so we don't have to move the camper to refill and use a 12v submersible pump so we don't have to lift the heavy water containers to fill the tank. There are no waste tanks so we use blue totes to haul off the waste water too. The cassette toilet holds about a weeks worth of bodily waste and can be dumped in any toilet when full - no need to find an RV dump station. It's much cleaner and more hygienic than handling a nasty RV dump hose too (see the movie RV).
The money you save in gas towing a camper with a low frontal area, like an A-frame will quickly pay for itself. I still get around 21-22 mpg towing my 1,700 lb Aliner (and over 30 mpg when not towing) even with all the miles on the clock. It handles hills well, just not on cruise control, and whatever you get to pull it with, be sure and get a camper with electric brakes or add them like I did. Here's a link to a Blog entry I wrote about my experiences with one.
http://www.cheaprvliving.com/which-vehicle-to-live-in/living-traveling-pop-aliner-trailer/ The camper itself has been very durable, just be sure and have the bearings packed at least once a year and put good tires on it for safety sake. You will have to replace the seals and bungie cords and recalk a few spots every 3-4 years but that'd pretty easy and inexpensive if you do it yourself.
Good luck,
Chip