Apple Support Selective
My bro bought an Apple laptop a coupla years back and when the hard drive failed the local official Apple dealer in Belgium claimed it was caused by a memory sim failure (wot?) and the warranty had been breached because non-Apple memory had been installed.
This was astonishing to me: a) every laptop has the facility for users to add memory of the correct type, of any brand b) the memory had been installed at the time of purchase by an official Apple dealer c) my bro had paid extra for Apple Care.
After some shouting, they replaced the hard drive, incidentally, leaving the third party memory in place.
A friend returned his iPod to Apple's shop in London just outside the 12 month warranty and rather than repair or replace they merely offered 10% off a new one. Somebody at Apple hadn't looked at UK or European consumer law which (roughly speaking) holds that the retailer's responsibility for consumer durables well exceeds any notional manufacturer warranty.
Arguably, a warranty is simply an undertaking for a fixed period after sale by the manufacturer to underwrite the retailer's responsibility to repair. It's a contract between the maker and the seller. In the US this may be the consumer's only protection, but not in most of Europe -- and we tend to pay more for the same items, partly for that reason. Warranty wording always states that the terms do not affect consumers' normal rights.