Have to jump back in.
We drove both of our Tacomas (4 cy single cab, extended cab v6) with six pacs
campers all over the west, Baja and never had any structural problems.BUT
i did improve mounting points in both cases by adding metal straps on all corners to spread
stress areas out.
As far as clearances the only worry is to be aware of height when off road.
All camper of any make can have problems.
our fwc ended up with cracks on the upper rear door frames (i think other have had this
same problem)
After ripping out the turnbuckle tie downs on a trip to Baja following 1000 race course
i added turnbuckles to the four corners to help keep fwc in place.
On this same trip i was able to also crack the frame at the rear spring mount
did not notice till arrived home.
Campers and trucks for me are to be used so far all problems have been fixable!
Just my thoughts and experience, yours may differ.
Les,lqhikers