Hate to burst YOUR bubble matey , but ive done it before , and works a treat , ive done this on 2 concours cars for various shows last year and used boiling water on them everytime and they went exactly where I want them to.
But you do have to fix them to a straight edge whilst you let them go cold , then they will stay straight. If u dont let them go cold whilst they are still on the straight edge they will just bend to all shapes.

To fix back to the car all you will need 10mm dry fixing glasier tape which is exactly the same as original.

Ben