hi there tiger tiger seal is unbelievably a good product i would say the best. i first came across it years ago on a marine aplication im sure ive read somewhere it will sticlk and seal under water. ive bonded all sorts with it including my saph front windscreen rubber fuk nows how im getting that of if the time comes.dont use the double sided tape as you dont need it. lightly key the mating surfaces with 180 grit rubber will scuff also dont use tape to keep the black magic in let it ooze out a bit hold the spoiler in place with another fantastic product gaffa tape where ever it tries to lift. whipe the worst of with a rag where its oozing out and then soak a good rag in either pannal whipe or meths or even acetone also known as nail varnish remover pannal whipe is slightly better than the others but all theses dissolve the black magic goo and it will blend in like magic leaving no edge. the black goo gives you plenty of working time but dont fuk about if you get on with it that is. even if it starts going off the these products will still break it down. try a bit first on somthing and see how the pannal wipe etc works blending it in. be warned though wear rubber gloves as your black hands wont be going anywhere near your birds nick nicks for days on end