types of cars?

swapping roof racks between cars is not a simple swap over, you need specific clips for each car and they arent cheap

my advice
look for a used set of yakima q-towers and crossbars
get the appropriate q-clips for each vehicle
used bike rack, steelhead or anything better
ski rack, one of the newer ones, they are less prone to freezing up when at the mountain and being a pain in the ass to open
dont forget your locks, put them on the towers themselves and then on the bike and ski racks also

it will take an hour or so to swap the system from vehicle to vehicle, but its the best route for a solid rack system that will last the life of the vehicles and then some