My SO and I are planning to build something that my Subaru Forester can tow, yet have some more comforts than tent camping can provide. Teardrops naturally came to mind, but we also wanted a little more "storage" than most designs I've seen have.
We may also upscale to a 5x10 or 6x10 trailer as a base which will adjust these plans somewhat.
Our plans include:
- Under storage area, approx 16" tall. Full extension slide drawers at rear (kitchen and assorted items), slide out at sides (misc), plus a hatch access that is full width of the trailer (storage of 11x11 popup canopy, chairs, poles, etc.)
- 15 gallon water tank (Friend is giving us his tank and pump)
- Deepcycle battery, charges off roof mounted solar or car when it's running (with Auto-transfer-switch)
- LCD TV inside with built in sound (car stereo w/ DVD player)
- Exterior Canopy for side. (kinda along these lines: http://www.pinterest.com/pin/100627372897233934/ )
Here's my initial whiteboard idea:

And layout for the "Storage" (still undergoing change):
