5 years later and I'm back for more advice. Sorry I never updated this post with the final build! It took 1-2 years for it to be "done" completely. As once I got the shell and could go camping I was unmotivated to finish it until winter. We take this out every other weekend at minimum in the summer up the Rocky Mountains with no problems. It's reached Teton, Yellowstone, Glacier, and Zion NP's (among many others). I'd say we have >10k miles on it at this point. I never thought a foamie could last this long!
My nerdy self kept a spreadsheet for cost and weight. We were around $3,500 for the full build including all tools, power tools, hitch, and car towing accessories. We put about $100-$150 a year in it to fix or upgrade one thing or another. Calculated weight was ~750-800lbs unloaded.
Briefly here is what I've done year by year:
Year 1 - Shell of camper complete. Ready to roll. Continued to add waterproofing. Scrapped keeping food storage in the back.
Year 2 - Added divider and back galley. Can't figure out waterproofing, always entering through front window. Added layers of paint to no avail. Ended up adding tarp under mattress. Curtains!
Year 3 - Upgraded baskets in the interior to a fixed shelf. Re-waterproofed the bottom with roof tar. Attempted to grease wheel bearings, couldn't get them out. Bought new standard axle instead.
Year 4 - Crappy axle had stripped/misaligned threads on one side. Replaced one wheel hub and regreased bearings. New trailer tires. Upgraded hatch weatherproofing with a strip of trailer roofing rubber.
Year 5 - Found the used front window had a holes drilled in through the framing (emergency window I never opened because it was blocked by the tongue box). Finally found and sealed the source of water entry! Replaced lights with LED before realizing failure was in the car not the teardrop. Hatch blew off, in need of fix (
viewtopic.php?f=21&t=70637 )
Once I can figure out how to put up pics again I'll include them. I just wanted to update to show any skeptics that foamies can last and be a viable teardrop. It's worked perfect for our towing constraints. We get around 18-21mpg in our Subaru Outback towing it loaded for weekend trips. All our trips involve high mountain passes.