Let's get you up to speed. At 2017 Eurobike Dahon displayed their new Curl tri-fold bike. Brompton filed for an injunction, claiming some sort of IP infringement. At the first hearing, Dahon showed the Curl to the court and pointed to the 9 new, unique EU patents the bike's design had been awarded. The court threw the case out and ordered Brompton to pay Dahon's legal costs.
Sincere thank you, that's useful.
Now if you can pull a rabbit out of your hat and answer the question of why the Curl D9 is nowhere to be found for sale, you would be contributing more good knowledge. Maybe because the earlier Curl IGH didn't sell? There are a few rare folks on here that have the latter, but neither are currently for sale, even though Dahon USA still shows it on their homepage; (Note that it is a mirrored image (chainring appears to be on left side), possibly to disguise that it is the earlier IGH, and not the D9 which had been advertised in recent years, though price never specified; Easy clue is that the front caliper on the D9 was *forward* of the fork blades, not behind.):
