I have a P38 Range Rover Vogue 4.6 V8 Petrol, with Nicholson McLaren SRi Autogas which I don't use as it's faulty.
In July 2012, whilst parked on a camp site in Lincs my 4 hazard lights came on [and stayed on]. They weren't flashing, just stuck in the 'on' mode.
Disconnected battery overnight...