Tires: tire pressure-audi a4, tire shop, vehicle manufacturer

Question
My Audi A4 (2.8 quattro) lists the tire pressure at 36psi for "normal" conditions and load.  I just visited a tire store and they insisted that 32psi is appropriate for my replacement tires - Continental ContiProContact (205/55/16).  Can you weigh in on the correct pressure?

Also, what are your thoughts regarding nitrogen to inflate tires rather than just compressed air?

Thanks in advance for your time.

Answer
There are really two responses I could give:

1)  The vehicle manufacturer spends a lot of time and effort and puts its name next to its recommendation.  Did the tire shop do anything similar (write it down and put its name next to it)?

2)  Did the tire shop tell you why 32 psi was the right answer and 36 wasn't?

Obviously I believe the vehicle manufacturer has the right answer and I can't imagine why the tire shop could give an answer without consulting with the vehicle manufacturer.

OK, nitrogen.  Has some benefits, but most of the hype is just that - hype.  If they give it to you free - Cool!  But I wouldn't pay extra for it.