If you are talking about the eLongate kit we've ordered one a few weeks ago. 2CH input only however, good for a carpc or a ipad set-up. Not sure if this will work for your 4CH deck? Unless you don't care about the F/R fading then it should be fine.
Mate here got it in hands on the unit, goes in his 987 to try the infotain we're putting together atm. That infotain's got digital 5.1 Surround so fading can be adjusted by software
ps; pay attention when shopping, seen 2 other MOST converters locally but FM modulators instead. No exp with this kit, no idea what it is in fact, but I'm sure we don't want that.
That's the one we end up getting at the end...