Auto insurance claim estimate inaccurate California
My 2024 honda accord was side swiped by another car recently. The driver side mirror and the side of the rear bumber (the part right next to the rear wheel on the side) were damaged. I filed a claim with their insurance since I have dashcam footage that makes it very obvious I was not at fault. The insurance company sent me a website to upload photos of the damage, which I did. They later sent me an estimate that does not include any details about the bumper, only the mirror. They told me to go to a shop and ask the shop to work based on that estimate, when I asked them why they didn't include any details about the bumper, they said the adjuster made a note that it was due to existing prior damage. I have no idea how they determine that. Anyway they told me to go to the shop and ask the shop to supply them a supplement for any additional repairs which they would then need to review. I have not been in an accident in more than 20 years and so this is all new to me. In addition, if the repairs take some time I think I should be reimbursed for a rental car, but they did not mention any of that. Should I push the insurance to give me a more accurate estimate, or just go to the shop and hope they will accept any supplements they send?
Edit: clarified where exactly the damage occurred on the car.