I adore the free in-house designs of that era. Like the Dodge Charger III & Dodge Deora. They had that certain late sixties "touch".
Pure custom cars are not my cup of tea, though.
The Deora was an outside project, built by the Alexander brothers, (and penned by an ex-GM freelancer) that Dodge fell in love with and added to their traveling show car stable. The brothers wanted to build a cab-forward pickup-based custom, as these smallish trucks were suddenly proliferating in Detroit. They had planned to make the rounds of the Motown auto makers, soliciting a donor truck. Dodge, their first stop, said yes. Ironically, the builders favored a Dodge-based custom, feeling that maker's truck was the least attractive.
Personally, I find the Corvair Rampside less pleasing, visually, though more intriguing mechanically.