According to the OP posted link, if the driver doesn't have his IRS tax return with him ( a facetious comment in the link) and the LEO has any suspicion its a commercial use, he cites the driver and says tell it to the judge. Hard to believe a decal constitutes enough suspicion to warrant a citation.-What link are you referring to? I did not post a hyper link.

The link also mentions transporting fuel in a "non DOT approved fuel cell", I don't know of any DOT approved racing fuel cells.
-Again what link? Correct Racing Fuel Cells are not DOT approved , hence the citation

So now you know why I said "What???"