Wow... sure am glad I outgrew that "My Car Is My Temple" mentality.
No offense to those who still suffer from it, I used to as well, I'm just glad I can enjoy my car without all the raging paranoia and hostility some people seem to have. I've worked hard to get my car, hard to get it back on the road, and I'm thrilled as can be when someone likes it enough to say something, or offer to buy it, or (clutch the pearls) dares to put a piece of paper on the windshield (the dirty heathens!)
It's a car, not the Lost Ark.
Sorry my friends, but some of you guys sound an awful lot like that hot busty babe who likes to walk around with her boobs hanging out, and then getting all offended when someone notices. You're driving a very desirable car that brings back a lot of cherished memories for a lot of people, and to both cases you've got people who will be interested in buying it. You can say no without being rude, surely, snobby, or in any other way disagreeable.
As for those jerks who put the advertising fliers on the car windows, direct your .45 at them. They've got it coming!