Is his mother being a narcissist?

Firstly, let me say this is my car before we get into the story. I let my husband drive my car more than I do because he does doordash to make extra money when he does work. So, at some point the car broke down and needed to be fixed and we were fine with the car being down for a while until we got the money. His mother decided to “get the car fixed as a birthday gift” 😒. From that point she decides to start demanding he takes her everywhere. So we started planning a trip to go out of town for his friends sons party. The day of she decides to say “You can’t go anywhere until I get off of work at 4:30.” He tells her “the party starts at 2:30 and he would not be able to pick her up.” So we get on the road and she calls about 3 and proceeds to say she’s ready to be picked up. We tell her we are no where near her because we had already left. She proceeds to get upset saying someone needs to come get her or send her a lyft because “she told him she got off at 4:30”. He eventually sent her the money which I told him not to because she’s going to keep thinking it’s okay to just demand him to do things. Fast forward we get home… she tells me she’s mad at him because “he thinks his friend is more important than she is that he couldn’t pick her up from work”. She says the car is only running because of her but then she tried to twist it and say “I mean I did it out the kindness of my heart” and that she’s “going to talk to him and tell him how she feels”. I think she wants to take advantage of him because he has intellectual disabilities and she knows it’s easier to get under his skin and make him feel bad. I want to say something but I don’t want anyone saying I’m getting in between him and his mother. I think I am about to start taking my own car until she understands the fact that the car is not hers and just because she got it fixed “out the kindness of her heart for his birthday” that he is not obligated to take her everywhere she needs to go.