Thanks for the reply. I tried a quick wipe but it appears the marks are on the inside. This fits in with the installer's explanation that it is glue from the factory.
Hi all,
Had some new panels installed last week here in the UK via an MCS installer. Went up to the roof for the first time to check them out and noticed that one of the panels has some sort of residue inside. The installer says that it is excess glue between the frame and panel, and it is...