My favorite was a tow truck I did for a repo company:
"I want my logo as big as you can make it on the side of the truck"
So just in case, I printed a layout for them . . .
"That big? I did tell you we were in the repo business didn't I?"
So, I resized it down to just the door, gave him the option of premium or reflectorized, got the job and picked up the whole fleet of five trucks. Premium.
The next month he comes back in and wants a quote to have it all done over in reflectorized. The quote amounted to about quadruple the original job. (Stripping the original job, cutter blades, special order vinyl and add conspicuity stripes)
"Holy (expletive deleted), you gotta be kidding me. Don't you just glass bead the stuff that's on there?"
Explained the details, benefits (again), process and got the job . . . again.
Sometimes I love it when a customer isn't happy (with their choices)