A place for more technical discussions. Please make sure you post in the correct section on the site, this way it keeps the site tidy AND ensures you get a more relevant answer.
Well speaking to a mate today, he said his - on a disco 2 it has to be said - is on the roof bar and the bar itself provides a decent earth. Currently mine is bolted to a cross bar not the roof rails themselves.....which happen to be metal. Will try bolting the mount to that, now I have longer bolts the mount should fit round! Shall update tomorrow!