XX4 design copy?

[racingdwarf]

Reading how well darren did with the xx4 in the euros thred and also seeing the new Xray 4wd that is said to be "another BJ4we copy" I started to wonder why so many cars have used the BJ4 type layout but no one has copied the xx4? is it a copy right patent thing? did losi spend a fortune on patent rights and Jconcepts did not.

ok fair enough after the xx4 a lot of 4wd's motors headed up the front of the car, but I have yet to see an xx4 clone

I'm not saying the BJ4we wasn't a great car, but the xx4 seems a legend and the other legendary car, the RC10 inspired many other 2wd designs