Insurance agent here, I usually chime in on insurance related topics.
First of all, like many others have said (and this is for future readers, not the OP), if you are involved in a similar incident as the OP. Don't report to your carrier if the other carrier is accepting liability and cooperating. This avoids a few things:
- You being out your deductible (yes, you should get it back if your company subogrates against them, but this can take weeks)
- A claim is now on your accident history. Yes, it will be coded as not-at-fault and should be zeroed out if your company subrogates, but its still there and still can cause problems if you ever move to a different insurance carrier in the future.
- If you file on your own, hopefully you have rental car coverage, otherwise you'll be footing the rental car expense yourself until you can be reimbursed.
- There's no certainty that your carrier will treat you any better than another party (such as in the OPs case). I've seen many claims and it's rare when one is treated differently just because they are your own policyholder. Companies and adjusters usually try to stick to the policy language and pay claims that are payable, regardless of who the party is.
However, if the other carrier is not cooperating, dragging their feet, arguing over shop hourly rates etc, then go ahead and report it to your carrier and let them subrogate.
I went through this exact same scenario. My Model S was 4 days old, less than 100 miles, and someone backed into me. My own carrier knew nothing about it, and it was handled 100% by the other party's insurance. My record is clean, I was never out a dollar (they set up rental, no deductibles, etc.). Now, I did have to haggle with them on diminished value, but other than that it went smoothly.
To the OP, you've already gotten good advice from others about working with USAA on the labor rates. Put pressure on them about the warranty, and get the shop involved if need be. They are used to dealing with adjusters.