I've just had the lid retaining strap fail and the lid hinges snap. Joy. The replacement hinges in metal which shouldn't need a strap are supplied by:
Zycology with offices covering UK.
BMW replacement hinge (Metal)
Product Number: E6-10-430-50
Just plug the part number into a search engine and it should come up with all the details needed. All the info was originally found on a US site. Hope this is of help.
PS. Has anyone got pictures of this mod for keeping your ally boxes on the frame? Mine don't have them and I'm having to be extra careful to make sure they're locked on. It can start to make you paranoid!