For those interested...

I own a 2000 S80 and the usaspec ipod adapter works great with my 2000 s80. From everything I've read the usapsec solution is much better than the ipod adapter sold by Volvo, primarily because it allows direct control of the ipod rather than the "hack" mentioned in previous posts for the volvo adapter. Also, it costs less.

The usaspec adapter will work with 1999 and 2000 s80's, contrary to the compatibility chart listed on the usaspec.com website (actually, in one place it says yes to the 2000 and in another it says no - but either way, it works). My s80 has the hu-801 receiver, but I imagine the hu-601 will work fine as well, considering it has a similar changer input. The only cautionary note is that the adapters sold from Crutchfield say that they're updated from PA-10 to PA-11 but most aren't - which is what I encountered. Upon hooking it up, the CD6 light kept blinking and I couldn't control the volume or change from CD6 to CD5 (CD6 is the aux input on the usaspec adapter for satellite radios, etc. CD5 is the ipod). Usaspec is aware of the issue and they will gladly update the software on your adapter to the true PA-11. Works like a charm now. I don't know if this affects S60/V70 models. I do know that it affects the S80's, at least the 2000 S80. In fact I now remember hooking up my brother-in-law's 2002 V70 and it worked fine right out of the box. Of course it could have been a PA-11 that was truely a PA-11.

If you plan on hooking up a satellite radio (I've got Sirius) then you should purchase a ground loop isolator (rca in to rca out - inline from your sirius radio to the usaspec adapter) or you'll here a hum from the satellite radio when listening while the ipod is attached (even if it's not running). They cost $15 at best buy.

Hope this helps anyone who is interested in ipod (and satellite) integration with your volvo, specifically for those of us who have the 99-00 S80's.
Good Luck,
Jason

BTW, I supplied power to both units through the cigarette lighter using a wire jumper from radio shack. The actual name escapes me. You'll need to at least remove the hvac unit to get to the cigarette lighter and/or the radio if you wish to mount the satellite radio with your favorite homemade device. There are several posts on how to do this. You can find some pics here: http://www.carstereohelp.com/strvolvo.htm

Any idea if this info will work on a 2001 S80?

Yes. The USA Spec adapter works for most 2001-2005 Volvo's (according to their website). This post is to inform the 1999-2000 owners that the adapter works on these years as well - at least on the 1999 and 2000 S80 I installed it on.

How do USAspec update the software? Can you do it over the internet? (excuse my ignorance)
I also have a HU801 and I read elsewhere that there was a problem fitting the USAspec to some HU units because of a right-angled connector which stopped the HU unit being slid back into place. Was that an issue for you?
Mick

Send the adapter to USAspec and they update it at their shop. You get it back within a few days. I didn't have a problem with the hu801 and the plug. The hole for the radio on s80's is pretty deep. The V70 we did for my brother-in-law fit fine as well (which I think is the same dash as the S60's).

Jason
Thanks for the advice. I live in the UK, so sending it back to USAspec is a pain in the neck. I shall keep my fingers crossed that I get the right unit.
Mick