agreed,one of our joiners got fined for the same,his tax disc holder had come off and was only showing the top half,but it was enough for a TV to about turn and stop him.
st3ph3n i've had a van from Clarksons before with a towbar fitted,and it says so on their site.........http://www.scotlandcar-hire.co.uk/van-hire-scotland.html..........if it helps
my work has used this place for about 10yrs,never had any lettering fading or peeling off on the vans i've had,dont know if they do cars though John..................http://www.allsignsscotland.com/
passed a place today that looked like the scene of your off road trip.....was it just after the r/about between kincardine and alloa on the road to knockhill by ant chance???