[Canuck]

I bought a Mercedes E55 a few months ago and all body panels and key parts are identified with a coded number. even if the sticker is removed the number stays on the panel. MB have used a bar code ID system for many years,as far back as 1991 models.
Chrysler used a "secret" number on cars since the 50's. i just removed the heater box from my 1960 300F and found the number on the firewall. It is not a duplicate of the vin but it does identify the car a matching the body unit number and microfiche data.
I saw you stamp your car in 4 locations that are nor visible but easily locateable if nesessary.
Floor pan under carpet.
Bottem of doors.
trunl lid inner frame
rear frame rail.