Deb, unless you're looking at a different brochure from the one I have, I think you are reading it wrong. GE tickets do give access to Arnage and Mulsanne enclosures, but on foot.
The brochure I have says that only holders of the relevant parking passes can park in Arnage and Mulsanne car parks, but that a GE ticket entitles you to free use of the shuttle busses.