95 A6 Timing Belt and knocking?

["Clough, Samuel" <SClough@irps.atl.invesco.com>]

I just got off the phone with the dealer to have some things checked on the
A6 and some maintenance done and since the car has 58k on it, I figured the
Timing belt should be changed even though the service book doesn't mention
the belt at all.  The dealer said it didn't need to be changed until 90k.
Is this normal?  Having had a 944 before, I'm a little nervous about timing
belts, and assuming the 2.8 is an interference motor I don't need a top end
rebuild any time soon.  BTW, is some knocking normal on cold starts?  I'm
running 15W-50 Mobil 1 and when started cold in the morning (around 40
degrees here) the motor makes a knocking or ticking sound until it warms up.
It's not really loud, but you can hear it when accelerating.  I expect a
little lifter noise for the first 10 seconds or so, but this lasts longer.
I always keep revs under 2700 and use light throttle when it's cold, so I'm
not running it hard, but I'm just wondering if it's normal.