So now we have all these replies regarding whether it is possible to top up the electrolyte level on maintenance free batteries. Of course it is POSSIBLE but [as an example] suppose you keep adding distilled water to your battery thus weakening your acid solution in the process and lowering the effectiveness of your battery?
In any case this does nothing to answer the original query which was if anyone knew a particular reason why this problem exists on so many Crossfires and not on so many other cars with similar amounts of electronics.