[Treeve]

I'm saying it's not a requirement, and not in the ADR.

What I didn't say was "don't fit them".

The point being, we all get upset when some bureaucrat desk jockey makes up rules out of thin air; it's therefore important that we only follow the rules which are written down.

Re: general safety requirements. This covers radiuses and sharp edges. Again, no mention of heat or burning. The same ADR applies to motorcycles with exposed headers, yet no heat shield required on them.

In short: a consistent approach is what we should have, and hence follow the rules as interpreted by mass manufacturers... They're the ones making money via the ADRs!