I was having trouble stopping water leaking into the rear tray and decided to seal it ( standard problem with D40 trays).
On removing the standard plastic tub liner installed from new and only around 6 weeks old a I noticed a lot of swarf from where the importers had drilled holes for the fitting of the standard tray hard top had been left laying in the tray and they were already starting to cause surface rust on the paint work.
I would hate to thing what the state of the tray would have been like after 12 months.
I have since sold the tub liner and treated the tray interior with black spray on underbody protector and it has come up well.
Be aware you never know what's under the tub liner.
On removing the standard plastic tub liner installed from new and only around 6 weeks old a I noticed a lot of swarf from where the importers had drilled holes for the fitting of the standard tray hard top had been left laying in the tray and they were already starting to cause surface rust on the paint work.
I would hate to thing what the state of the tray would have been like after 12 months.
I have since sold the tub liner and treated the tray interior with black spray on underbody protector and it has come up well.
Be aware you never know what's under the tub liner.