The only silly thing about them is the 10mm bolt head matched to the 10mm thread. It rounds off or crumbles with rust very easily. Once I'd chipped away at the rust I had to use reverse spiral sockets, then a 9mm spanner to finish. Drowned the new ones in copper grease first and waxoiled the holes. Fine now.
Never been that far in, but probably behind the light fittings although a good squirt of waxoil in the holes would see to anything lurking in there. Not too much though otherwise you could goo up the wiring. As you say a dollop of copper grease on the threads and inside the rubber cap to [reserve the bolt head should they need to come off again. There is actually a plastic bearing/ bush assembly at each end of these straps which needs lubed too.