Laws for registering the XM2k in MO?

I'm not as educated as a lot of you are here so I can't read legal-eze, but I did find this:

Motorized Bicycles (Mopeds): Sections 301.010 and 307.180, RSMo define a motorized bicycle as any two-wheeled or three-wheeled device having an automatic transmission and a motor with a cylinder capacity of not more than fifty cubic centimeters, which produces less than three gross brake horsepower, and is capable of propelling the device at a maximum speed of not more than thirty miles per hour on level ground. Motorized bicycles also include motorized scooters.

Since a motorized bicycle is neither a “vehicle” nor a “motor vehicle”, the Department of Revenue does not title or register these units.

Persons engaged in the business of selling motorized bicycles do not have to be registered motor vehicle dealers; however, any retail store or dealer that sells motorized bicycles is responsible for collecting the sales tax due at the time of sale.

Motorized bicycles are not subject to Missouri’s financial responsibility laws, nor Missouri law requiring the operator to wear protective headgear. The operation of a motorized bicycle is prohibited on a public street unless the driver holds a valid operator’s license. The operation of motorized bicycles on interstate highways is also prohibited.

So what happens when the XM2k gets up to 31MPH? Or when it tops out at 43MPH, what laws does it fall under?