Originally Posted by tjls
This might be the case in the UK, but I am pretty sure that, in fact, such a corporate posture is illegal in the USA under the Magnusson-Moss warranty act's provisions about availability of all service parts and documentation to third parties (in the US, companies cannot require you to use their authorized dealers for service, whether warranty service or not).
I don't believe this is true. They can't force you to use their parts or labor for warranty-required work you have to pay for (i.e., if you don't change the oil we'll void the warranty). As I read it, though, they can control who/how the work is done for free warranty repairs. Specifically:
"No warrantor of a consumer product may condition his written or implied warranty of such product on the consumer's using, in connection with such product, any article or service (other than article or service provided without charge under the terms of the warranty) which is identified by brand, trade, or corporate name"
Note the "other than article or service provided without charge".