Why did Atti key Arash's car?
I presume it was his, but maybe not. As much as she keyed it, you'd think there would have been some scene of him finding it later and reacting.
But why did she key the car? Was it because he took over for Saeed (The Pimp) and was now the primary drug dealer in the area? We didn't get any indication Arash treated Atti bad the way Saeed did.