OK so I tend to "Cabin Up" my car during the winter months, when salt is on the road, and plug my Optimate 6 to the battery to keep it topped up and ready. I hadn't realised the M4 had a Lion battery until I went to connect my Optimate 6. So I am correct in assuming I cannot use the Optimate 6 and, if not can I use this?
http://www.optimate.co.uk/optimate%20lithium.htm