DICE or VAIS?

Since you have a 2004, both would work pretty good. There are minor differences, like VAIS uses RCA plugs for AUX input and DICE uses 1/8" plugs. Also the way the playlists are done. DICE has a new model and is cheaper, but VAIS seems to have a longer track record.

I got a DICE mainly for price ($159 for the DICE vs $299 for the VAIS, non group-buy). I don't care if one can do more playlists than the other. I don't even have an iPod yet. I have my portable XM radio attached to the AUX imput and it works great.

I know others will chime in with more information. Also I suggest you do a search and see the threads, like
http://priuschat.com/index.php?showtopic=18651 and http://priuschat.com/index.php?showtopic=21095.

There's a couple of things the VAIS has over the DICE. I needed a Ground Loop Isolator for the AUX input. I already had one, but that could add $16 if you need it. The VAIS is supposed to have one already built-in. Still that's still a wide difference in cost. Another advantage is that you can upgrade the firmware of the DICE at home if it's necessary. I can't remember if you download the firmware from VAIS into your computer and then plug the VAIS unit into your computer, or that you download the firmware into your iPod which sends the firmware.