Those china specials are what are often referred to as "grey market" cars. Typically an individual and/or a small business will pay to have a batch of cars brought over and they can have one car certified/inspected etc. and have it applied to the whole shipment, making it more cost effective.
(Most of the Mercedes G-wagons you see are also grey market. Mercedes didn't officially sell them here for decades.)

Those micro trucks are imported as "off highway" vehicles, intended for "farm" use. (how they get around Federal standards) Some states allow them on surface streets.
Some of them are pretty cool, actually! I like the little Subaru one.

As far as I know, there are no specific laws against RHD, from a sales or licensing standpoint. But then, apart from having owned 2 RHD vehicles here in Colorado, I'm hardly an expert.