is it this
RealOEM.com BMW E53 X5 4.4i Battery charger
the plug on this fits any power point so the ashtray should be good
I had visions of it plugging to diagnostics so I had to look up the part .
says on that link dealer should print instructions from aftersales assistance portal ( ASAP ) .
afaik these should only be connected when engine is off .
unplug charger before starting engine .