Typically, car insurance follows the vehicle (not the driver) so if you were to file a claim, it would be under your friend's insurance. However, I would exercise caution when considering filing claim. Deductibles are usually between $500-$1000 so that might not offer much help. Also, this type of claim would be rated as an at-fault accident. In California
last year, an at-fault accident raised premiums by an average of almost $900
. Most companies will rate (i.e., charge) you for your claim for 3 years. So that $900 will triple over the period you are being rated for. So, if you can afford it, I would recommend paying for that damages yourself rather than involving your friend's insurance company.