Ye's used vehicles are open for bidding at Musser Bros. Auctions ... and the owner of the auction house, Harold Musser, tells us Ye recently sold 6 cars back to his local Ford dealer in Cody, WY.

We're told the Ford dealership turned around and enlisted Musser Bros. to auction off Ye's fleet ... the listings went up this month, and there's already a ton of interest.

Seems Kanye was a Ford truck man ... the haul includes 4 of 'em -- a 2016 F-350, a 2017 F-250, a 2018 F-150 Raptor and a 2019 F-150 Raptor.

Rounding out the fleet is a pair of 2020 Ford Expeditions, including one XLT Max edition and one Limited Stealth edition.

As you can see, Ye's cars all have matte black wraps ... but we're told the winning bidders can plop down another $250 to have the wraps removed. They're all 4-wheel drive too, for all you off-roading customers.

It makes sense his fleet is up for sale -- remember, he's also listed his sprawling Monster Lake Ranch for $11 million. Owning multiple heavy-duty trucks makes sense on 4500 acres of ranch land, but not so much for his new beachfront Malibu property.