Why was none of the A-main finalist's running 2.4ghz radio's at the worlds?
 

How come nobody in the A-main was running the 2.4ghz radio's and receivers in their buggy's at the worlds this year?

Because the system isnt legal in Japan for use, as of yet. Although ive been told it should be made legal shortly.

Do the USA use the same 2.4ghz systems as us?

Thinking of buying one when I'm next there, but they don't do 40mhz etc!

Spectrum is a US based company :) http://www.spektrumrc.com/