After extensive repairs by Apple - logic board, I/O board, display, hard drive, battery - the issue was still there.
Apple offered me a new MBA but as I'd already crashed all the MBAs I'd been allowed to touch - they soon put a stop to that when they realised they wouldn't have a working machine left on display - unlike others, I left them dead - they decided they had enough evidence.
UK consumers are protected by the 1979 Sale of Goods act. As the MBA is unfit for purpose, it went back for a refund as Apple were unable to guarantee they could provide me with an MBA that would work.
Mine started OK but got worse and worse until it would crash whilst sitting still with no activity at all, remote or otherwise. Totally unacceptable for a £1,000 laptop.
I now have a Samsung notebook, which I like, and WIndows 8, which I don't but it's reliable and won't quit half way through a presentation to a board of directors and refuse to wake up until after we had lunch - not a professional look when bidding for £200k of work, which can never, ever happen again so I cannot own an MBA.