rack feet to fit the prius c's door frames

so i'm wanting to contribute to the roof rack compendium...

i live in hawaii: LOTS of compacts & hybrids & LOTS of roof racks.

i'm tired of rolling up towels and strapping my paddle board to the roof of my C2. getting old, quick. and it's clear from the other threads that there seem to be no offerings of roof rack feet for the prius c. here's why - according to two independent sources i've spoken with:

clip-on feet need at least three inches of flat roof in order to sit flush and stay in place. i understand that rhino is selling for the c (not meant to be an attack on rhino), but i've also heard some of mixed results. it seems then that rhino is simply repackaging their feet for the standard prius - again, this was confirmed by the two sales guys i spoke with. they too had heard of feet (of various brands) coming loose on the prius c (while driving fast with a board on top ).

so does anyone know anything different? i desperately want a rack so that i can get back to my favorite spots around the island. with my towels and straps, i don't leave town and drive very slowly. i miss the confidence that comes with having a hard rack.