Am I being rude?

I have people stop and talk about my projects while working on them. Usually they are from the neighborhood and have been watching my progress for a while. I usually enjoy the experience and I am pretty cordial. I haven't had any bad experiences with it and I use it as a resource to ask if they know of any (insert item here). You never know who might be a resource.
I have had a couple people ask if I would work on their cars. That is always a hard no.