The short end which goes into the bolt head is too long to fit into the curvature of the roofline, which is sloping toward the sides of the car roof and meets the roof rails in a "V". Using the stock tips (they come with several sizes) the stock wire fits me perfectly, and is extremely comfortable. Theyre not terrible but just not my taste for everyday or work wear. Easy to take on and off! I will likely use some glue to fasten the sliding part to the "split" piece and to fasten the female cables within the sliding part. as far as size go up between 2/3 SizesDepending on how tight your clothes are you will see the zipper underneath a lil. He still cant believe it and hes calling everyone he knows so he can hear them in stereo, listening to songs from Queen and the Beatles to hear the audio panning for the first time. It does look huge as well, and when its full its hard to fit in a locker. These slippers are awesome and in not upset at all for the under $20 purchase. These work okay for inexpensive casual footwear, however I walk on the outside of my feet and these tend to slip to one side.