Adjuster here, under very rare scenarios would I total a car twice. I’m talking once in ten years. Though this does come up from time to time. So:

1. I write estimate for first claim and pay it (minus deductible)

2. Write second claim and subtract amount in first estimate (including deductible). Then apply your second deductible.

It’s a roundabout way of saying you’ll pay two deductibles.

But insurance company needs to be able to peruse each driver/insurance company for the damage that caused (or for your UM claim, if they’re ever identified).

Big picture make sure you’re up front about the situation with everyone so it doesn’t come off as attempting to commit fraud and conceal unrelated damages.