Right I have a customer car arriving soon, pre chaved up by the owner :/

Anyway one of the things he wants me to sort is the bonnet scoop which he has stuck on and filled the edges to smooth it in......oh dear.

Now I thought about removing the scoop and tigersealing it onto the bonnet and then pop riviting it in place, but what can I use to successfully smooth off the edges of the scoop without it cracking? a bit of tigerseal around the edge as if i was sealing in the bath (thats a DIY tip btw ) or something like Isopan bumper fill?

Any help would be greatly appreciated!