The only input I can add it that it is common for fluid to be a little thicker when it's cold out, causing your power steering pump to work a little harder to get things moving. But it should quiet down after driving for a few minutes. If it doesn't it may be your power steering pump going bad. Any chance you didn't use Audi power steering fluid in it?

 

The way I've been able to work bubbles out of the power steering in the past, on other cars, is to get the front wheels in the air, and turn the steering wheel lock to lock several times, with the reservoir cap off - doing that circulated the fluid and with the cap off, having the system unsealed allowed the bubbles to bleed up and out. It didn't always clear all of them, but it got rid of the majority. Of course, on these cars, that'll probably trip a fault code