I dont think supaglue is waterproof, and will peel away again when wet.Also it will harden and become unflexible.
As you may or may not know, i had splitting roof material right behind my drivers seat and i bought some of this
http://www.toolstation.com/shop/Adhesiv ... 420/p55262
Which i stuck too the roof material using evo-stick, seems to be holding for the moment.
I have plenty that i can send you too try out if you like.