NigelatMSG,
Unfortunately, cell phones is one of the areas that I'm just not knowledgable to speak on. I realize this is a Samsung forum and you have a legitimate Samsung question, but you might try reposting this in C|Net's Cell Phone forum located here:
http://forums.cnet.com/5204-7817_102-0.html?forumID=74
I wish I could help, but I just don't think I could give you the answer you're looking for.
--HDTech
I have two Z500s of slightly different vintage. One [the more recent of the two] will pair with the Ford Audio [Sony] unit ok, but the Ford unit almost immediately declares it 'unavailable'. The second will pair and remain connected but, if I try to take up its offer of sharing its phonebook with the Ford unit, this fails and the 'phone is then declared 'unavailable'. My wife's less functional [no 3G] Samsung both pairs and shares its phonebook without a problem.
Could the problem be related to either more recent or more functional 'phones? I've seen suggestions that the Bluetooth on modern 'phones goes into a kind of hibernation mode to conserve power, and that Bluetooth units in [some] Fords and most BMWs can't handle this.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic