Electric go-karts are da BE(A)ST. LOVE THEM ! I've ridden several, and on one was able to hit 110 mph on a wonderful road track in Ohio. The money the guy put into that one was unreal. But so was the ride.
And Check out these respective electric recumbent BEASTs too. Like electric go-karts, I absolutely love them because they are low to the ground, more aerodynamic than bikes, and with low center of gravity you can just fly through curves and feel like Mario Andretti, except without the noise, the gas, while you get some invigorating exercise with basically massive turbo boost.
They can be designed for some wicked off-roading as well. Some day when I 'get rich' I wanna build an off road track for people to ride these, that is like a Lemans type of track with several miles of roadway, super smooth pavement, incredible turns, and some cross over/under bridges. I'll charge a modest fee for entry, but its more for the pleasure of it for people to have a chance at having some different fun away from traffic and our terrible roads, and mediocre trails, and have no expectation of profiting from it. Probably will be a loss but who cares ? (you can't take the money with ya)
My favorite, which i am 'saving up for' is the 4000 watt mid drive that will hit 45 mph, and has the option of a 4500 watt hour battery (possible 200 mile range). There is also the QUAD recumbent, which would be super fun off road.
Some day I'll likely own a collection of these, but need to sell a ton more ebikes, and pay off some college educations first. In the meantime, I have done a number of conversions of recumbents that have been fun for customers, but nothing on the order of these beastly boogers that have MASSIVE batteries in a really great location, basically super low and make them like slot cars in terms of staying stable on the ground at very high speeds.
Super comfortable riding positions and seating can be achieved on these, and your own leg power can really be effective since your back is fully supported...