I am fitting a grp rear panel (over the original ally one for strength) what should i use to bond the grp to the ally?, will PU be OK or is there something else i should use?.

Cheers

Ray

PU is fine, id rough the ally up a bit as well but no probs with PU. Clean everything down with Acetone first as well (the back of the GRP will probably have wax residue on it)

The only problem i have encountered with PU adhesive was when bonding abs wheel arches to my old Mk1 golf Gti (now sadly sold). Even after roughing up they didnt stick too well (Sikaflex). For everything else the only problem is that the bugger wont let go when it has hold. Quite amazing how good it is but as NSDev says - make sure surfaces are clean and dry and not too smooth.