AITA for not letting my friend borrow my car after how she returned it last time?

I (27F) have a decent used car that I worked hard to pay off. It’s nothing fancy, but it runs well and I take really good care of it—regular maintenance, I keep it clean, no smoking, no trash left inside, etc. I’ve always been a little protective of it because I rely on it every day for work.

A few months ago, my friend (29F) let’s call her Sarah, asked to borrow it for a weekend trip because her car was in the shop. I hesitated but said yes because we’ve been friends for years and I wanted to help.

She returned it two days later with: Less than a quarter tank of gas (I’d filled it before giving it to her), Fast food wrappers in the back seat, Dirt all over the passenger floor, And the cherry on top: a mystery scratch on the back bumper she swore “was already there” (it wasn’t) I didn’t say much at the time because I hate confrontation, but I was honestly pissed. Especially because I expected more out of someone who I am friends with .

Flash forward to this week,she texts me asking if she can borrow my car again for a different trip. I told her no, very politely , and said I just wasn’t comfortable loaning it out anymore. She seemed to have gotten upset with me and was saying things like “are you sure you can’t just help me out, I feel like that’s what friends do for each other” like I feel like she’s guilt tripping me idk.

I responded initially but now I’m waiting to reply to her. But now I’m getting messages from another mutual friend saying I’m being too uptight and that it wouldn’t kill me to help her out “just this once.” I feel like I’m being guilt-tripped for setting a boundary after already being taken advantage of once.

Am I the asshole for refusing to let her borrow my car again?