Hey all, thanks for the complements.
As for any heat flowing out of the vents, I haven't noticed much yet. As saline mentioned the 22 degrees where her is, I have only been in cold temps, since I have installed then. I'm not expecting to see a temperature difference on my gage but this summer when I'm driving through the desert, I have to believe there will be more air flowing through the front grill.
Herb, I would have left the carbon fiber finish but I couldn't find a carbon fiber hood for a 2006 E350. If you know where I can find one, I'll strip the black paint right off those vents.
If anyone does want to do this, don't hesitate to ask me for advice. I did a few things different then the instruction that came with the vents suggested and I would be more then happy to share what and why I did.