HU850 replacement?
 

My hu850 unit has died in my s60. The sound is intermittent and chooses to blast my eardrums out for short periods of time, mostly I can't get anything apart from a hissing noise. I've looked at repairs or another hu850 which both are expensive. My s60 is the 2006 facelift, will any other oldear head units fit? I don't want to lose the sat nav etc, so don't really want to go the after market route.