I would be surprised if they could.
I tried to read the federal laws covering years and they are pretty incomprehensible.
In 73 cars came with separate shoulder belt that you could attach to the lap belt, or not.
I carried it with me for some years in case a cop stopped and I only wear the lap belt.
I have been stopped a few time over the years.
The only time a cop every said anything was when he was in his car at eye ball to eyeball level and could see the shoulder harness in my roof.
I would image most of the state laws say "seat belt".
Not "shoulder harness" anyway.
