>>977054...continued...
Before the video bikes took over around 2010 (there is about three or four teams running them now, that they built themselves) probably the fastest bike was the Varna Diablos. These were built by a guy who raced and sold them, there was three slightly-different versions over about 5 years I think. I dunno how many were sold, but I doubt it was more than 10 or so.
It's enclosed and has a normal windshield, but it's still very cramped. Since you can't even get in and out of it without help, it's not really good for normal riding. (the tops are taped on for racing, usually)