I imagine some of you are already aware of this, but I figured I'd post it in case anyone wasn't aware.

I replaced my A/C compressor recently along with the accumulator and figured may as well replace the orifice tube while I had the A/C system open. So I reached along the high-side line that runs along the driver's side strut tower area and... nothing. I was expecting a fitting but it was one solid line to the evaporator. Wouldn't you know it, there's an expansion valve at the firewall where the lines connect to the evaporator! I guess this was a revision of the W-Body A/C system. Rock Auto lists both an orifice tube AND an expansion valve for the 04-08 body.

Thankfully it's exposed to the engine bay, so if it needs to be replaced the evaporator doesn't have to be removed.