Yeh I can remember some of the old poorly fitted systems which operated on illegal wavebands causing local radio interference. If used today you would need a hands free kit
I was thinking that earlier out in the car. we used to fly round the country lanes with Mic's flailing all over the car. No worries about the hands free then.
We used to check with the guy in the car infront to see if the road was clear on the otherside of the humpback bridges. R5's and Mini's didn't really have quite the same image as the General Lee