Myles seems to be riding his luck, he messed up with the "Chinese Cats", messed up waiting for the flag, and seems to be hiding himself by being seen to always be doing something!
While the "Retro Caravans" weren't an easy sell the guy did say he'd sell at least 6 or so, so the team should of been able to sell at least one, and Leah proved it was possible. His sales technique was awful as was pointed out, one of the first questions you ask is "Are you interested in buying" and a good salesman should be able to answer that himself within a few minutes of talking to a customer.