It turns out that the E-Z-Go power golf carts are manufactured by Textron Corporation, which also makes Cessna jets and Bell helicopters.
So why won’t they go faster? 
In a sign of the times, it turns out the company is laying off 120.
Golf Carts, Jets and Helicopters
They do go faster if you can get them airborne 8=)
Did you ever see the commercial about how to get a volkswagen to go 100 mph? They dropped an old Beetle from a helicopter. I can’t remember which model it was that they were advertising, but it was neat to see them poking fun at themselves in the process.