Finding the vehicle value is AFIPs problem. They will guesstimate
I traveled back an forth every 6 months to Chile with a car with Chilean plates. after several years a Customs Officer at the border Cristo Libertador , went inside and printed my exits for the last years. He said you are residing in Argentina and drive to Chile for a week every year,,,! Next time I will impound the car and you will have to walk to Mendoza to see a Judge, to release the car after paying the fine....
I drove to Chile and sold the car