Guys,

If I supply a microphone (I have a spare genuine aftermarket Kenwood bluetooth mic - same as this, different connector though)
Who can make me one of these - this one appears to be the Subaru bit at £140 quid
Discussion/questions/updates about "Stock head unit information..." FAQ thread - Page 7 - NASIOC

I could probably do this bit myself - but it does look like a right old bodge up.
Stock NAVI Bluetooth...on the cheap! - IWSTI.com: Subaru WRX STI Forums