If you want to stay safe, 60K miles would be the time to change it
(tensioner, rollers, water pump, etc. as well).  The owner's manual
suggests much higher limits, but these things are known to fail
prematurely and you really don't want to be stuck with an engine full of
bent valves, unless you have some sort of an extented warranty that'll
cover the repairs in case SHTF.

http://www.bentleypublishers.com/tech/audi/audi.2002.maintenance.sched.pdf

Cheers,

Pete

The early 1.8Ts were cursed with the "spawn of the devil" cambelt tensioner
which was the cause of a good number of premature failures and an 80K
service interval. Since about late '99 this was fixed with a new design of
tensioner & so technically the interval on yours is probably 105K miles.
Personally I wouldn't leave it much past 80K but also have the inspections
done according to the schedule - that way if anything happens you have
compied with scheduled maintenance. Speak to your dealer - you may find you
have 100K/10yr powertrain warranty now depending on whether you are the
first owner or not.

All in all its a bit of a lottery & so if you think the engine has been
worked hard then change it earlier - its a lot cheaper than getting an
engine rebuilt.

I