"O-okay, I-I'll l-look after y-your car-ar, s-sir…"
"Good! It's infront of the building. Big, purple and green, looks like my head. Can't miss it."
guy shuffles away and finds the c-
BLAM!
"It needed a new paintjob, hoohoohoo!"

Don't fall for it, there's probably a joke to be had with you looking after his car so he can kill you.