To get accurate answers, I'd try Edmunds.com and click on "research" cars, where you can also compare the stats/features side by side. I do know that the 07 has rear curtain airbags, whereas I don't believe the 06 does.
From what I gather on here & some other sites, they improved the TRAC system sometime in the 07 model year. I'm sure someone here can confirm this.
I've picked up a Prius brochure every year since I bought the car. As far as I can tell the only real change was the addition of the Touring package for 2007 and continuing in 2008. The other changes are marketing. Options have been repackaged, some becomming standard while other standard equipment became options. In 2006 the side curtain airbags (front & rear) were in the lowest option package (good luck finding a base Prius). In 2007 they became standard. It is possible that computer control of various systems has changed over the years causing different behavoir so I'll leave that for the more technically savvy.
Please check the Knowledge Base section. I have meticulously created a thread with all the options, changes and colours.
That's pretty good. But I didn't see changes in the MFD. In 2006 it changed to NTSC video I believe (which is why the CANView doesn't work after 2005), and in 2007 they changed the graphics somewhat. Wish there was a better way to tell them apart. For people who knew the old VW bugs, you could identify almost every year by minor changes here and there, but to the casual observer they all looked the same. For the Prius I cannot tell the 2006-2008 models apart (except Touring, then I know it's either 2007 or 2008).
The MFD, I don't know but what I do know is that the backup camera models have the newer MFD with higher resolution while non backup camera models get the old 2004/05 MFD. ahh... yeah I can't tell the Beetles apart. In Canada, all Touring models are 2008s.
