At a recent race, Kidderminster national to be exact, I got what could be described as a "bollocking" for putting the numbers on the wing, and one on the roof i think.
I was told they aren't allowed on the wing ?!?
I confess I dislike putting huge number stickers over the windows of a buggy as it takes away from the scale look and if you read the rules:
22.1 Cars entered for Off Road competitions will be reasonable representations of full size cars generally accepted as being suitable for Rallycross, Rallying, Trail and Desert races.
Since when is a huge number over the front window "a reasonable representation" any way ?
There is no mention in the rules that the numbers need to be on the body shell at all, they can be on anything, including the wing or even the ariel tube.
Am i right or am i right ?

we'll see at tiverton when I turn up for heat 1 sporting numbers on the ariel tube.

(and a copy of the rule book in my pocket ready for any "back chat" I receive from the officials)