Automobile insurer total loss valuations in Pennsylvania, CCC One, and state database

I was involved in an accident in Connecticut while traveling from my home in Pennsylvania. The other driver was at fault – veered over the center line into my lane and struck my vehicle in the front. My insurance is with GEICO and Pennsylvania is a No Fault state. GEICO evaluated my car and declared it a total loss. The adjuster presented the offer.

I have read here about how insurers often use CCC One to determine the Actual Cash Value of a car declared a total loss. I understand this is NOT replacement value. In my case, it is a 2015 VW Eos Executive (highest trim level) with only 55,000 miles. There are no comparables within 1000 miles. I could find only two in the entire country. The adjuster also told me they also rely on a Pennsylvania vehicle value database to determine value – something I am not familiar with.

I have asked the adjuster to provide CCC One's data to me, and understand that they sometimes make mistakes or use comparables which are not identical, but then adjust up or down, with the adjustment always favoring the insurance company, not the policy holder. I also understand I can hire an independent evaluator out of pocket if I disagree with the valuation.

What is this Pennsylvania vehicle valuation database and how is the data compiled? If it is based on values reported on private sales I would be suspicious since the price in these transactions is often underreported in order to save on the sales tax.