Things to keep in mind:
Kei trucks in the US can be considered mostly in two separate categories:
- As toys on private land/farm equipment: You can buy them from sites like the one above, including brand new. They will not be registered to ride on roads. They might, or might not be, less expensive and better suited for farm or private land work. They are real vehicles, meant for real work. But you will be driving them on private land, and they will never have the status of a vehicle.
- As road vehicles: They have to be imported as classic vehicles under the 25 years and older rule. There are importers for that too. Once registered, they can be used as any vehicle. Note that 64hp (or more) on a 1700lb vehicle is not something to sneeze at. These things are snappy and fully able in traffic. Most can keep 80mph. It's just that they are SMALL and they are a deathtrap if you get hit - consider it as safe in a crash as a trike or a sidecar on a motorcycle.
The hidden part of the iceberg: there's a concerted effort by a private organisation to get them banned under every shape and form, under the pretext that they are too dangerous on the road. Whether this organisation serves the recreational vehicles (ATVs, UTVs, etc) manufacturers' interests or not, is unknown.
They have been VERY efficient in the last few years in working directly with state DMVs and having not only new registrations banned, but also existing registrations taken away. They instruct the DMVs on all the loopholes that can be used. Typically, it's things like a VIN shorter than the standard US VIN length (not all countries used standardized VIN lengths 25 years ago), which results in a "Missing VIN characters" verdict.
Owners groups are fighting back, with some success here, less success there. At the end of the day, the final decision is local DMV. Except I believe in Colorado where things went so bad and owners fought back so hard that the issue blipped on a few radars and things were made better.
The East Coast was very heavily hit. There's light at the end of the tunnel currently, but few know if it's the Sun or an oncoming train.
The main thing in this whole story is that so far this fight has been completely underwater. The Autopian is pretty much the one media that is covering it extensively and following up on developments, then picked up by the bots at whatever remains from Jalopnik. Other (otherwise worthy) sites as Ars Technica have been openly hostile or at least misguided in their (few) articles on the subject. But even there, the one article that was borderline foam at the mouth hostile to them seems to have been edited recently, at least in its title.
While this battle might seem ridiculously insignificant in its scope given the quantities involved, it can metastacize in unexpected repercussions. This "Missing VIN character" axe can tomorrow fall on that beautiful collector Ferrari, or on that million bucks Nissan Skyline that makes the pride of so many collections. Indirectly, the whole world of 25+ yr old imports is threatened by the creation of such precedents. Used to be an imported collector car could be registered in 99% of the cases when all the legal paperwork was in order. No more.
As they used to say in the old country - The King allows it, but the crossing guard forbids it.