Low Tide:

First, I'm no expert in radios, speakers and the like.

What I can tell you is that the HU-801 in my S80 is wondeful sounding. It fills the whole car with glorious music and volume can be turned up to enormous levels without there being any distortion.

We like the in-dash 4 CD changer in the HU-803 and we have no tape cassetts anymore so the HU-613 was not suitable for us.

We've had such good experience with the HU-801 in the S80 and didn't really give it a second thought when considering the XC70's HU-803.

I can't help you on the specs differences other than to say the HU-803 should be a very good radio and CD player. We've had no problems with our HU-801 and would recommend the HU-803 without any reservations.

I'm expecting the HU-803 to sound even better in a wagon as apposed to a sedan.

I have noticed that the face of the HU-801 in our S80 can get very hot and is quite disturbing. It may simply be the great heat given off by the twin turbos and exhaust manifold driving the S80 T6's engine. The engine bay tends to run with high temperatures and the twin turbos sit just on the other side of the firewall behind the center console.