Erratic turn signal operation can be a result of a failing turn signal flasher relay which will require replacement.
Car Problem Reports
Volkswagen GTI Flasher Relay Failure Can Cause Erratic Turn Signal Operation
Volkswagen GTI Problem
Average Mileage: 105,333 mi (80,000 mi - 126,000 mi)
Visitor, 2002 Volkswagen GTI, 126,000 mi
Turn signals suddenly stopped coming on. The next day I used the hazard light button (which houses the flasher relay), and the signals started working again, but unreliably. About a week later the relay failed completely and I had neither turn signals nor hazards. Part is easy to replace and costs about $14.
Visitor, 2001 Volkswagen GTI, 110,000 mi
Right turn signal fails to operate intermittently
Visitor, 2004 Volkswagen GTI, 80,000 mi
I'm at 95k miles now and i drive 45 min to work and this morning is the first that it continued the "clicking" noise the entire time. Talk about annoying. Just gives me another reason to blast the music ;)