Was there any features optional on the 2006 that became standard on 2007 or 2008?

Was there any features optional on the 2007 that became standard on the 2008?

Anyother significant differences of the 2006 v 2007 v 2008 HCH?

 

I don't believe there are many significant differences between the years. I know that with the 2008, you get a Tire Pressure Monitoring system (TPMS) which the 06 and 07 don't have. This is the result of a new law that requires all 2008 vehicles to have TPMS.

 

Slight firmware differences went in in '07 that made it easier to use EV-Glide, but I think that's really about it.

 

Little things like the hood and truck liners differenciate the 2007 from the 2006, along with the XM Radio ready in the audio system.