I bought two of these tire holders to go on top of my car (one for my wifes bike, one for mine) hoping to save some space on the inside of the car. They do work although I had do do some modifications to make them work the way I wanted to. The first time I used it to hold the tires, it looked like the tires would wobble right out. The wind from driving shook the tires and made them wave. After I lashed them together I didn't have that problem. The other thing we were worried about was the fact that there is not a locking device on the holder. To eliminate that problem I took a cable style bike lock and looped it through the tires and the Thule support bar (which is locked). It works perfect with these mods.