Here in UK I think the legal trail is through the dealer you purchased from. WhenI fell out with a British car manufacturer about work I considered should be warranty and the factory didn't, I told the dealer I was very reluctantly taking them to court, as my lawyer told me I couldn't take action against the manufacturer but had a watertight case against the seller. I then informed the carmaker of the same. Miraculously, all was suddenly solved and work done and payment refunded.