hello,

My kids complain that the sun beats in on them in the rear (black leather) seats and the A/C is ineffective.

Anyone know if dark tinting will help?
Do they make louvers for 2007 GP's?

Dark tint will help and closing the moonroof visor will help as well. Unfortunately cars not equipped with rear climate control ultimately do not have the temperature control the equipped counterparts. For what it's worth, my parents have a new GMC Sierra with full load including the rear vents but I find they pale in comparison to the front vents. It's the joys of a car unfortunately.