I drive an electric car but I've got a petrol lawnmower. I actually need to go and get some petrol because the lawnmower is empty. I've no idea what the etiquette is on walking up to a forecourt and asking to jump the queue with my gerry can (a la skipping the queue in a supermarket if you have just one item), but the alternative is driving an electric car to a petrol station to fill up a can which I suspect would look like some pretty deranged panic buying itself.

Not that it matters, because there is no petrol left around here anyway.