The Hyundai dealership nearby is having a sale (50% off MSRP), so some of the people I work with are kicking around the idea of buying one, waiting for the sale to end, then selling it.
I feel like between having to register, insure, finding a new buyer while paying interest, and the fact that you changed the car from 'new' to 'used', there's not any profit to be made there. And if there was, someone would already be doing it. And if someone wanted a Hyundai they could buy a new one during the sale, so the only market is people who didn't want it new during the sale but do want it almost-new at twice the price, which is not exactly a seller's market.