It’s a…
A homeless man knocks on a woman’s door, looking for help.
“Think you could spare a few bucks? Maybe some food?”
The woman thinks to herself for a few seconds, then says, “You could do some handy work around here, I’d be glad to give you $30 if you paint my porch. There’s some green paint and a brush right around the corner”
He thanks her, and heads towards the bucket. She returns inside and resumes her knitting. After about an hour, she hears a knocking again at her door, and goes to open it.
She is greeted by the same man, green paint splattered on his clothes and in his beard, a wide grin on his face.
“All done ma’am and by the way, it’s a Cadillac, not a Porche.”