I have one of these available :
http://www.wheelspinmodels.co.uk/i/68290/
I bought it for £80 for my RB5, used it no more that 4 times and only in practice, it has never been used under race conditions as I have only been racing my 4wd.
Will accept £45 posted.
Im only getting rid as I have now converted my RB5 to the Vega conversion so it now takes saddle packs.