I would like to see the look on the next person's face who hassles me about the crap on the floor of my car (I suppose, only if I actually told them what I thought of what they just said to me)

Let me point out a few key things about the abovementioned statement:
"... floor of MY car"
"... crap on the floor..."
"... only if..."


It's a fucking car
It's MY fucking car
I DO take care of my investment
The functionality of a car has very little to do with what rests on the floor mats (I paid extra for the fucking floor mats to protect the carpet by the way, but that doesn't matter does it?)

but I won't say anything to mr/mrs next hassler because really, they are just trying to be helpful right? to make me a better person, or something.

So, I guess it would only be apporpriate to thank mr/mrs next.