Thanks for your thoughts though I think ageing of the Polystyrene foam is a myth as the material is not degradable, well ok, very slow biodegradable. I can see a bit of logic in those little impacts you expose your helmet every day and the glue issue here might come to play, you never know what's being used. In terms of UV, other than graphics damage it doesn't sound convincing (integrity wise) unless your lid heats up to 100C. Don't get me wrong guys, I'm not that tight but after 5 years (almost 6) for now I feel my lid is in a good shape, it's been well looked after..