I would disagree with many stops delivering vehicles.
Let's say they have 20 vehicles to deliver: 10 going to Denver, 10 to New York City. And let's say they have 2 haulers, each holding 10 vehicles.
They're not gonna load each hauler with 5 for Denver and 5 to NYC. They're gonna load 1 hauler with 10 Denver vehicles, and 1 hauler with 10 NYC vehicles. That way, the Denver-bound hauler can drop-off and return to California. And the NYC-bound hauler doesn't have to stop in Denver to unload anything.
Will they make stops for fuel and rest breaks for the driver: absolutely. Will they make many stops throughout the country to drop off 1 or 2 vehicles along the way: nope. They're gonna optimize the routes as much as they can. So yes, a hauler will take longer than you or I could drive cross-country, but it's not like they're gonna be stopping constantly to unload vehicles along the way.