Neighbour coveting my car: not getting it

So I have a 2003 Cavalier I use only when my other car is in the shop and my neighbor's son is hot and bothered about buying it. No idea why he wants an old standard-shift Cavalier with a big side dent so badly but the family, who I do not know at all, came to my door en masse about 7 years ago to let me know they noticed I don't drive the car and they would like to buy it. This immediatley made them seem like stalkers. I mean, first, why are they monitoring my vehicle use, and second, why would they feel the need to tell me this and suggest that simply not using something means they are entitled to buy it? If they hadn't said that, I would have considered it but it felt super weird since I had no idea who they were, where they lived, or how they know what car I drive, you know? I had to take their word for it that they are even our neighbors because unlike them, I do not monitor those who live around me. I'm busy. I was outnumbered and it was creepy.

I had actually considered getting rid of the car, but I told them it was not for sale and assumed that was the end of it.

Since then, about once per year one of the parents comes to my door or scares the crap out of me approaching me in the back alley of my not-safe neighborhood to say their son wants to buy our car (anyone seen Better Off Dead? It's starting to feel like a super slow, drawn out version of the newspaper kid). The kid must be in his late twenties now so it's not clear why mommy and daddy have to do this for him (his immaturity doesn't make him more endearing), or why he hasn't found another one on Craig's List in the intervening 7 years since there were a ton of these cars on the road in the 2000s. Last time it was mom and I thought I could shut her down by saying that if I ever changed my mind I would let them know. Which should translate to, if I don't let you know, it is NOT FOR SALE.

This should not be complicated. When you ask someone something once, and they say no, it means no. When you ask again, you are applying pressure by not accepting the initial response. When you ask 7 or 8 times, you are a harrasser. Also, stranger danger, it's a thing. Think about that when you go to someone's door without an invitation.

I feel like I should approch them next time they are out and ask if I can buy his shirt, or her shoes, or maybe their house just cuz I want it, you know?

Anyway, the dad just interrupted us during work by ringing our doorbell to ask yet again and we told him AGAIN we are not selling the car.

But I lied. I actually intend to sell the car very soon but not to them.

Here is the life lesson about entitlement:
My husband and I are very generous, but super private as we are on the spectrum, so I never sell old goods. I give them to someone who needs them. I've given quite a few items to my neighbours, including a brand new $1400 Chariot bike trailer I gave my neighbor for their new baby beause I won it in a lottery and didn't feel right taking money for something I did not pay for. If the car-coveting kid had approached us himself, politely, without pointing out that we do not drive the car and making me feel weird, and simply said he liked it, there is about a 90% chance I would have given it to him for free or just asked him to do something small like mow our lawn. Instead, I will probably donate the car to charity.

Entitlement will get you nothing. And spooking people in a high-crime area to ask for a favour is never going to work in your favour. A note in the mailbox would have worked wonders.