In fairness, Bob did the same thing on more than one occasion. Trucks and even vans were called "cars" on occasion.
I'm sure Drew knows the difference. I mean, trucks and vans and cars all have different icons on Money Game and Pass the Buck so it's not like there aren't reminders of the different types of vehicles floating around.
But what does it matter? In the grand scheme of things, it's immaterial, as long as the contestant knows Drew's referring to the thing with a windshield, four wheels, an exhaust pipe, and a license plate. As rodroddyfan said, the contestants have eyes. The only place I think it makes a difference is in Rich's prize copy; if Rich calls it "a new car" a contestant might see the prize differently than if Rich calls it "a new sportscar," even if everything else is the same.