" he lives with his old affair from 15 years ago"
It seems like only anger coming from you. 15 years is a long time. It's not the current situation. Is it just her or would it have been any woman that you would not like at all. I ask as it feels like you have left a lot out. I don't think he is trying to buy your love, I think he does not know what to do to make you accept the divorce happened. He wants you to love him and accept that he has gone on with his life. A life that sounds like you don't want to accept. Don't think you are alone in this many have gone through it.
As for the Audi, that sounds like your fixation and not his. If he wants to give you a car, as you do not feel comfortable using public transport due to COVID than take it. That is not being materialistic, it's being safe in today's world. Remember you are the one asking for the ride. With the car, you would not have to ask again.
Try this book or others out.