From what I’ve heard from people close to Tecstar, the issue wasn’t VINs directly. The issue was paying tax on the manufacture of a vehicle. Apparently UP bought VINs from Shelby that were stamped and destined for cars but never used. These VINs never had a manufacture tax paid on them. When UP added the Shelby VINs to the new chassis they had bought (I guess they were buying new chassis from a vendor), they never paid the manufacture tax.
Makes a bit of sense. I haven’t read up lately to see if that is being reported or not though.