Disagree on double parking 100%.
I always parked my Z as in photo above at supermarkets, DIY stores etc. (i.e. anywhere not paying where there was a high chance of being damaged) part in protest and part to stop it being damaged.
Why would you use only one space? Don't understand that at all. The parking spaces in the UK are ludicrous. They are simply not big enough for cars. Haven't you noticed? Quite a big design fault that is accepted for some unfathomable reason.
Why would you squeeze your car in to a space designed for a go kart when there is a good chance of it either being damaged or you have to get back in to the driver's seat by performing acrobatics whilst your passenger stands in the cold, windy, pissing rain whilst you reverse out because they couldn't get back in at all.
I posted the photo in tribute of excellent Z parking, not for any other reason.
I'm sort of in agreement with you here.......providing there's plenty of space for others as well - if the carpark was busy, I wouldn't do it
as an example - I parked in a (paid for) car park in Staines over the weekend - pretty empty, but within the lines and nothing close to me - when I came back the following morning, the carpark was still empty, but my car had a car either side of it with not much room to spare