But you don't understand the VIN system.
That would mean that for all the different types of vehicles from all the different manufacturers, there would be at most 36 x 36 or about 1000 different WMI numbers available for US built-vehicles.
The different manufacturers include, Ford, Mercury, Lincoln, Mack, Dodge, GMC, Volvo, NUMMI, Honda, Honda motocycles, American LaFrance, Toyota, Lexus, Infinity, Nissan, Catapiler, John Deere, International, Harely Davidson, American Indian, Prevost, VanHool, Artic, Polaris, Suzuki, Motor Coach Industries, Thomas, Freightliner, Olds, Pontiac, Chevy, Hummer, Kawasaki, Suburu, AMC, Jeep, Seagrave, Mercedes, Plymouth, Chrysler, and hundreds of other manufacturers, including trailer makers. And a lot of these makers have more than one VIN, for say buses, chasis only, car, pickup, heavy-duty truck, SUV, etc.
Originally, only one number (1) was assigned to the US. Later 4, then 5 was added. That is why ISO (the people who came up with the VIN system) assigned
1 to the US, 2 to Canada, and 3 to Mexico. It would have been simpler and made more sense if 1, 2 and 3 were assigned to the US, and 4 and 5 to those other North American countries, if ISO knew that the US would need more than one.The other thing you'll notice is that when you look at VINs, all the ones for a particular type of vehicle for a particular manufacturer start with the same digit. Ford uses around 73% US components in its vehicles. One would think that some vehicles are more than 70 and some less, like 63% (e.g., Ford Mustang according to newspaper reports). But all Fords have VINs that start with 1.None for the same type of vehicle in that brand start with
4 or 5. In addition, sometimes Mercury or Lincoln had to go back to get another WMI number for a new line of vehicles, like SUVs. So when Mercury or Lincoln builds SUVs, the VINs start with 4 or 5, even though they are built on the exact same assembly line and the reported domestic (US + Canada - I know, you claim the VINs only reflect US content) content is identical across different brands, so it would 70% for a nearly identical Ford SUV. Even the Hummer gets a 5.Finally, if you read the actual US code (the code is the actual regulations that are written by US gov't departments required by US laws), there is not one word about content in the description about VINs.
All you have been able to do is say that your retired engineer friend said that the different digits indicate different content. You obviously didn't know, so what makes you think that a different engineer would know? That's something for the marketing or legal departments to know, not the engineers. You have not posted anything that backs your claim.
Jeff