body kit installation problems

[Peter]

I bought a stillin body kit, front went on ok, had to do some modification to get it working.

But my sides are a big problem. I got them lined up cleaned it with paint prep cleaner on the body and the skirts. They did not line up worth a crap at all, and now about a week later the skirts are pulling away from the car, the dam double stick tape is giving away.

I even got the prep pads that my body man said to use that helps to make it stick better.

What should I do? What did I do wrong.