Just thought it is worth noting.
I used the GoFasters number plate mounting kit to mount a 2009 CRF 450 number plate to my 2013 GasGas 300. To be fair I only used the upper bracket to assist in mounting. I used the headlight mount pegs on the stock front fender. I had to drill alignment holes to allow the crf number plate to slip over the pegs and stay put.
It seems there is a lot of wiring behind the plate so I mainly fitted the plate to allow for the wiring to not "squeek" I will play more later. Ridepg.com graphics are very, very nice.
So, I wanted black rear number plates. So first thought, buy 2014 plates. Nope, does not work, you need a 2014 airbox to allow for this not a big deal but I will have to buy some 13 number plates instead!