[calgarygeologist]

It has been many years since I've been through a write off. They sent me an initial offer and I went to my adjuster and asked for their comparables which, as you mentioned, were from their JD Power system. My vehicle was somewhat rare at the time and I remember they only a few comparables which were being used to generate my offer.

I went on Autotrader and I might have also looked on Kijiji and/or Facebook to see what I could find on the market. There were some listing which I found that weren't being used by the insurance company. I emailed those to my adjuster and told him that I wanted these included in my calculation and it obviously pushed my value up to what I considered a reasonable amount.

Basically, demand that they email you copy of the market report. Find your own comparables and negotiate from there.
Edit: I found my old emails with the insurance company and finding my own comparables and doing some negotiating resulted in a 10% higher payout.