AITA for not selling my car even though my fiancée refuses to sit in the front seat because my ex sat there?

Hi, everyone. I’m (27M) engaged to my fiancée (26F), and while we’re preparing for our wedding, something recently came up that’s left me confused and conflicted. I want to know if I’m in the wrong here or if her reaction is unreasonable.

Here’s the issue: My fiancée refuses to sit in the front seat of my car because my ex used to sit there. She says it makes her uncomfortable and feels like she’s “taking what’s someone else’s.” Instead, she insists on sitting in the back seat whenever we go somewhere, which honestly feels strange to me—like I’m her chauffeur. I offered to sell the car if it truly bothers her, but she told me not to because it would feel like she’s forcing me to do something. However, she still won’t sit in the front seat and avoids interacting with anything related to my past relationships.

This is part of a bigger pattern. She’s mentioned multiple times that she doesn’t want to do things I’ve done with my ex, like cuddling on the couch during a movie or visiting places I’ve been to before. I’ve tried to be understanding of her feelings, but I’m starting to feel like I’m being held responsible for my past, which I can’t change. It’s also confusing because she keeps in touch with her own ex, occasionally texting or calling him, which I have no issue with as I trust her.

Whenever these situations come up, she tends to withdraw emotionally—avoiding physical affection, not saying good night, or being distant. While I love her and want to work through this, I’m starting to feel like I’m walking on eggshells around her emotions, especially when they’re tied to things I can’t control, like my past.

TL;DR: My fiancée refuses to sit in the front seat of my car because my ex sat there and avoids doing things I did with my ex. I offered to sell the car, but she doesn’t want me to, even though she won’t engage with it. Am I the asshole for not selling the car and thinking her behavior is unreasonable?