Here is my take. Probably sooner or later most of us entertain the thought of building our own design. The initial thought usually manifests itself after some hands on fixing, mods, or restoring projects. I was no different than 100,s on here. For me it started with the HOOT ETV, I became a distributor for HOOT CANADA, and ONTARIO was mine. I really liked the Hoot (and still do), but thought a 2 seater (or more) with storage was needed.
So I designed the Bushwacker. Hoot slowly died, and then went belly up, and so did my hopes for the Bushwacker. I lost some money in the deal, but was bitten by the bug, so on came Bushwacker II (BWII), bigger, heavier, more HP, different tranny (T-20). I was still dreaming of production. Other ideas and versions followed.....
MY TAKE:
1. Body, use aluminum for proto-type, then go to Roto-Mould, less money than Thermoforming (Argo), you don't need to buy the rotational equipment, just pay for the mould, sub out production.
2. Design own tranny, don't get trapped by using competition tranny (T-20 or others), can use hydrostatic but it's been done.
3. Farm out production items, with back up suppliers, only assembly components.
4. Design should have suspension, tracks, be fast, style (Wedge), superior water speed, counter rotating tranny, no chains, and seat 2.
5. Final product must appeal to a broad customer base, and hopefully attract some ATV/UTV guys.