There are no installation instructions and it is not intuitively obvious. Fortunately, there is a video demonstrating this. It helps if one person slides it through the seat gap while another feels it on the other side (the Kia Niro EX has a flap over this area of the seat bottom). It was barely long enough to attach the retainers to the headrest posts, requiring a lot of tugging to attach. A variable length of this strap would be most useful, but not a current feature. Finally, it is to be fixed with hooks under the seat. I found something under the driver's seat but nothing under the passenger seat. The only bar deep enough to create tension was too thick for the hooks. You will need to add a loop (rope or zip tie) to this strap for the seat cover hooks. It's comfortable, it stays in place. May be easier to install in other car models.