Thanks for the replies!
Indeed, after doing some more research, it seems that the lighter does not work for our cars. My dealer misinformed me! That's a bit annoying, as I specifically asked about the correct one to buy. Hopefully they will exchange it for me.
Here is a link to the one I bought: http://www.amazon.com/BMW-Advanced-B...harging+system
Note: I bought it in person, not from Amazon. Not that it matters.
Now I need to figure out how to hook it up to the trunk. Is it possible to hook it up to the battery in the trunk and close the trunk? ///MPower-Belgium--have any pics or recommendations? Is the trunk connection suitable for quick connect and disconnect? I am drawn to that because I back in, and it would be less conspicuous.