I welded them to the car, once I removed the rear suspension. The front right corner was wiped out bad on this car, and it couldn't roll on it's own. Honestly, the casters couldn't quite handle the weight, and were deformed, and not worth the effort to recover. They did roll. We pushed/pulled the car up the ramps, onto the trailer. The left rear one got bent when the forklift came in, and actually pushed the car down on the trailer, before picking it up.