You really need a professional to attach the tie downs. I know this is a pain and can be expensive, but you are messing with the infrastructure of your vehicle. We chose the non-mechanical tiedowns because they are less expensive. Be sure to get the ratchet type and not the link and pull type. We had those at first and, because of a defect, they let go. Tyler's chair tipped over while I was driving because of it and it landed him in the hospital via lifeflight. Not recommended, believe me. The tiedowns have to be bolted into the floor in a specific location in your vehicle to allow for the size and type of wheelchair you are using. This means removing seats. It can get pretty detailed. Unless you absolutely know what you are doing, get help from someone who does.