The bowfiller cushions were designed by a Gulfstream Aerospace Engineer. They install by simply dropping them into place. They both have thick plastic lips underneath that slide right into the seat track. It takes less than 20 seconds to install them and pull them out. At 65mph they stay in place. I am good friends with the owner of the company that makes them and he is actually in the process of designing a backrest for the front as well. I can't wait to see it finished. I will be first in line to order that too!