Driver door with lower glass on front half...

I think they started that in '06. The early '05s still had vent windows and door mounted mirrors, the late '05s had cab mounted mirrors and one-piece windows with a straight bottom window opening. As far as I know, they did it to all the models that share that cab style, 379, 386, and then the 388 and 389 later.

I remember the first one I noticed with the '06-up windows-it really drove me crazy. I'm sure it makes for better visibility, but it ruins the lines of the whole thing for me when I'm looking at it from the side.

 

It very well could have been a late '06 thing. That would kind of make sense.

 

I believe it started with the introduction of the 389. My son's '06 379 has the straight door... but A-pillar mirrors.

 

This '06 has them, it must have been a middle of the year thing.

 

Well, I just figured out the real reason Peterbilt did this-they figured if they changed the window shape a little bit, I would get on Truckpaper and look at trucks this morning instead of getting out back and working on the one I've already got.