Some confusion is there in the industry whether containers or trailers loaded with vehicles ( UN 3166) need to be placarded or not. NO! no placard need to be affixed on them.
Those who had been handling shipments of vehicles in the past to/from USA according to 49 CFR wont have this confusion.
Shipping line OOCL has modified its booking acknowledgments of Dangerous Goods by including a weblink to a pdf file which will show the placarding requirements with instructions how to affix them.
This will be a good guidance to shippers to affix required placards correctly.
Read more on OOCL Site
IMDG Code Compliance Centre 