I am replacing my rigid molded Jeep oem mud flaps with some DIY flexible ones I have made up from insertion rubber sheeting. I copied the original lengths for now. Does anyone know what the legal length requirement is in NSW (ie height off the road surface or whatever measurement is used)?

Secondly I am putting small tieback chains on the rear flaps to keep them from being ripped off when reversing on rough ground. Has anyone done this and if so how?

Cheers
Glen