His choice. Depending on what cleats are on the cars. I would suspect that the cleats are of an old style and are not a swivel (up release type). I would use the swivels on the cross bar and get rid of the cleats on the cars. The old style cleats on cars were down-release and required a good line snap technique to release. That is why they went to the swivel cleats mounted on the cross bar in the first place. Current boats have swivels mounted right on the traveler cars.