Airconditioning

I have a 2005 Allroad that is heating up the external ambiant air temp by up to 15 degrees celcius, even when the temp setting is set to 'LOW' and the airconditioning switch is set to 'Econ'. So in theory, the temperature of the external air temp should be pretty close to what is being pumped into the cabin. On my Allroad it can be 25 degrees outside, but a professional temp gauge shows the air coming directly out of the fresh air vents is 40 degrees.

My Audi garage says this may be normal, but to me it seems strange, and would account why the car never really cools down on a hot day. I'm guessing on a 35 degree day, my a/c is thinking it's more like 50 degrees outside.

The Audi garage say the a/c is working fine, and say is drops the internal vent temp to 6 degrees (when tested inside the workshop, out of the sun). But on a warm day the system is pretty ordinary (luke warm).

Two questions:

1. Should the fresh air vents be heating the incoming air by as much as 15 degrees, and
2. Anyone else come across this problem.

I've been back the garage 5 times now, and could really use a expert's opinion.