1971 Duster Handeling

As nublu has pointed out, the body is generating lift. You have to get the air from under the car.

One example was the junky Daytona Pro Stock cars. Over about 150 MPH they generate a big amount of lift. You could help it, but it couldn’t be cured and pass NHRA bodywork rules.

They were a handful to drive and more than one guy told me they put mud in their shorts more than once with those cars.