Bought a set of Magnecor HT leads for my 220 Coupé turbo about 9-10 years ago (could even have been longer - I've had this car for over 10 years and the same model for 2 years before that), and they had been fine until recently when I took the king lead off the distributor cap and found it had corroded inside.
Emailed a photo to Magnecor and they said it was due to water in the terminal and not covered under warranty - but to send it back anyway and they'd repair it.
Popped it in the post, and very quickly received a brand new lead.
Pretty impressed with that - no messing around, not really even covered under warranty - so
to Magnecor.-Mark