Cleco's work great for some apps. but they lack strength. They are great for prefit panels with prefit holes especially on aircraft. But often when replacing body panel you find that they just don't fit. the panels have to be manipulated into position pulled, pushed, and drawn into place. I use a self tapping screw with a 5/16 hexhead. because they can draw parts together and prevent side slip. and find that Cleco's are inadequate when the amount of pressure applied is greater than they were designed to hold . Sometimes we used them in the shop but not very often. Also remember to weld both sides of the hole whenever possible.
View attachment 73304