As I am driving my 2009 Azerra, every five or ten minutes there is a soft to moderately loud clicking (or clacking) noise for a second or two. I have tried pinpointing the location but it is difficult. When I have other people in the car, we each think the sound is coming from somewhat different locations.

The noise is loudest and most frequent when it is hot and the AC is running, so I am guessing it is associated with the cooling system.

I have taken the car in twice. The first time, a technician did admit he heard the sound but noone in the shop knew what it was so the service manager said she would do some research. The second time, the service manager said she had read the Sonata was making some clicking noises in the moon roof, so she had my Azerra's moon roof serviced. That didn't help.

Before I take the car in for the third time, has anyone else noticed a similar noise or read about the problem elsewhere?

There are some muted relay clicks from within the dash as this or that ride/cabin air system application is enabled/disabled, but they are just noticible, not at all "loud"...

I'm glad you mention that a relay might be making the clicking noise. I have heard the same noise at different times and I'm looking to see if it"s the dash cracking over the passenger air bag. I keep my dash protected with a liquid protection and windshield screen whenever parked in the sun, hoping this will help prevent cracking.

It could also be the clutch solenoid that cuts-in/cuts out the a/c compressor.