Mine sat on the car on and off in the sun for 20 years, the weight of the hood scoop had it bowed down. I turned the hood upside side, put a little weight on it after a week or so, I put some reinforcing sheets of fiberglass across it. Works great now. The edges if you just lay something heavy on them, they will go back down to where you them, or close anyway.

At least worth a try.