Tigerseal bonded nearside front wing that I did myself has to date lasted 4 years, the offside that Caterham Midlands did gave up the ghost after 3 years - I don't know what they use as standard, but I suspect that it was probably more the quality of their work rather than the product used... (and the bonded bigheads used to attach the mudflap on the 'caterham' side also disappeared around the same time...)