As Charlie said, we are going to SPEEDWEEK in 2020. We typically end up with a 20ft container, but if there are more, then it becomes a 40ft, there's not much difference in costs and the more there are the cheaper it gets. But, what ever is in the box has to come back in the box due to the Carnet restrictions. The Carnet is a chamber of commerce covered assurance that you will bring back what you take out and pay no import or export duty.
We are doing Speedweek because it's busy but so what, that's what makes it special. It took us 6 years to get the record. Most of the bikes we ship have no V5. Ours started as a delivery of tubes and now has a billet engine. We have a frame and engine number but this is what we stamped on them so you can fill in the EPA paperwork. But once that it done, you can reuse it for every future trip because it does not expire.
I can write loads more however, give me a call if you want to know more or have any questions.