I'm a bit surprised they don't escrow or broker more than that. 5% seems like a hefty cut for just advertising when it doesn't cut down on the rifraf
they'd probably have a whole lot more liability as an actual dealership if they were more involved, but the online peer-to-peer broker-dealership I used to buy my i3 - KeySavvy - was smooth like butter and way cheaper than 5%. and got me a Minnesota dealer plate for 30 days immediately, too.
IDK how ebay works for vehicles.