I have an '06 V6 with ultraview. I have a Sears cargo shell. I purchased the GM roof bars and attached the cargo shell to the bars. I have probably an 1.5" of clearance and have little or no wind noise when driving at highway speeds. Just make sure you don't overload the roof racks. I wouldn't put more than 100lbs on the roof. I am not sure if the roof racks are for looks, or if they can be used for utilility. I can tell you I have used the cargo shell 2 times in the past year and have had no problems.