basically you can either have an air compressor already installed or you can fill them up at gas stations...You let the car start and run for like 5-10 min to let the bags fill up and then you can hit a switch and make the front go up and down along with the back....some people even have side to side. If you want to bounce with bags though I think you need at least 4 sets. I would highly suggest the cyclinders for the tour if you are seriously thinking about doing this. Not my cup o tea on cars but whatever you like.
