Wondering as I'm Wandering

WHEN STEVE AND I WENT  on our anniversary road trip in August, we saw this sign. We're not in the market for a car so had it not been for the hot pink paint, we probably would have ignored it. So do you think the maker of this sign knows something we don't? Did s/he employ some kind of esoteric marketing strategy? Pink definitely draws the eye but then it's like, what? Is it or isn't it? Did this the evidence of a husband and wife who can't agree? Maybe they'll pay someone 2k to take it away? 

Some things make me scratch my head. 

Here's another head-scratcher but also a jaw dropper. This town isn't known for a lot of gang-related activity, (knock on wood) so spotting this embellished wall blew me away when I saw it. Urban artwork along the back of a building nearby my work. 

It definitely gets your attention.

My photos don't do it justice. It's actually quite impressive.

So how did the "artist (s)" draw this? Was it done in stages? Was it done during the night, by flashlight? Did they get permission from the building owner? If not, how did they get it painted without getting caught? And do these symbols mean anything or are they just random silliness? 
I'm also wont to wonder about all the graffiti emblazoned on the sides of train cars as they whiz by. Why do people do this? Which people do this? I never see them. Are they homeless people?  Are they making a statement or just having fun? Do they wish they could open their own art studio? Are they starving artists waiting for their big break? There is some serious urban talent out there and I can't help wonder about the people who do it.  Any ideas?