The quality of the Mexican lenses is really hit-and-miss; some of them are quite good, others are garbage. It seems to go by part type rather than from lens to lens; the good ones ('64 Valiant, for example) tend to be consistently good and the bad ones tend to be consistently bad.
I will be notifying the Department Of Transportation of your illegitimate products. They have not been approved for use on any roadway in the United States of America and the do not have a D.O.T. E.O.# on them. when the D.O.T. conducts it's own investigation; you will probably not be doing business in the U.S.A any longer.
No, because DOT doesn't approve anything. Neither, contrary to common misunderstanding, does SAE. North American vehicle regulations do not work on an approval basis, they work on a self-certification basis: the manufacturer or importer of a regulated item of vehicle equipment certifies that the product meets all applicable provisions of all applicable Federal Motor Vehicle Safety Standards. On some parts, such as headlamps, the certification is made official by the maker placing an indelible "DOT" on the part. On other parts, such as all other lighting devices, no markings are required, though the maker may put whatever marks he wants to put.
Taillamps physically capable of being installed on vehicles made on or after 1/1/68 are regulated items of vehicle equipment, and so the maker or importer is legally obligated to assure compliance with the applicable standards. The Mexican lenses are not so certified, and because the maker is outside the US there is no jurisdiction for DOT or any other Federal agency to go after them. So how 'bout the importer? That's whoever orders a pair of lenses off eBay. That would be…
you! DOT and CBP do not have the resources or interest to hunt down and prosecute people importing onesie-twosie quantities of parts for their old Mopars.
And there is nothing such as a "DOT E.O. #". This sounds like you have the California Air Resources Board's aftermarket-part approval system in mind; there
is such a thing as a CARB E.O. number. It has nothing to do with lamp lenses.
And none of the rest of the repro lenses on the market, no matter where made, are tested or certified, either. Mostly they're just copies of an original, with whatever lens markings copied along with the rest of the details.
But after all that, if you want the name of the DOT's vehicular lighting compliance enforcement officer to report the guy in Mexico, send me a PM.