4 bikes on a tow bar style carrier

[R66bby]

Hey guys, i have had a search but couldn't find what i was looking for.
I have a renault grand scenic, i'll be driving from the south of france to wales at christmas time with our 2 mountain bikes and 2 racer bikes on the back.
It will look like this --> http://lib.store.yahoo.net/lib/orsracksdirect/2008...

My question is do i have to get something like a trailer board with the reg plate and the lights on etc as the original will be slightly blocked etc.

[R66bby]

oh ok, i was hoping for a no as per the photo lol.
time to find one over here and think how to install it.

[R66bby]

This is my car loaded, so I'm going to try and buy a trailer board later