Eddie - A lot of people actually velcro them in place so that they can be removed for an access hole. I tried to do that for a couple of days and just did not like how floppy they were. I ended up going to Home Despot and getting some 1" alum angle and pop riveting a small length of it to the top and bottom of the louvers. Then with the louver held in place by hand, I drilled four pop rivet holes through the body (2 over the louver and two below) and through the angle aluminium. Actually I drilled the holes through the body and "marked" the angle alum and bench drilled them. Then I countersunk the holes in the body so that the heads of the rivets would be below the body surface and pop riveted the muthas in. Body shop filled the holes and it worked out great.
Frank.