I go to a local cruise night a couple times a month, and I have very similar experiences as the OP. I have come to the point where I really don't like talking to the idiots though (I try to stand back and act like I don't own the car). I don't mind reasonable questions, but the idiots with the stories I have heard a thousand times are annoying.
I actually carry a bunch of SPF brochures with me and I have found it easier to just give them one when they get the confused look on there face when I tell them it is a factory built replica.
As far as touching, I seem to have more of a problem with fat ladies rubbing against it or bouncing their purses of of it because they don't fit between the cars very well.
