I have read through the forums for information on air conditioning on my 05/S4/4.2L and did not see anything like the problem I am having. I am expecting the worst (compressor) but thought I would get some input prior to going to my Audi dealer.

Prior to today I did not notice any issues but today was unusally hot and humid for this time of year. Anyway it was easy to notice that while driving around town at slow speeds I was not getting any cold air at all but once I got out on the highway (70-75 mph) it was blowing pretty cool or at least cool enough.

I stopped by my local Audi repair shop and they said that it did not need a charge, so they were 'guessing' it was the compressor and suggested I take it to a dealer for diagnosis and repair.

I'd be interested in any input you folks might have. Also if it is the compressor what else should I have done to this 72k mileage car since the front end will be torn apart anyway. Thanks for the advice.