Checking coated and outer plate for wear
WARNING: This page is about a different car, the 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Signs of overheating on outer plates point to worn coated plates. Evaluate signs of wear as follows:
A - Spots of discoloration of outer plate caused by overheating in distance of more than 20 mm: Outer and coated plate OK, can be reused.
B - Spots of discoloration of outer plate caused by overheating in distance of less than 20 mm: Outer and coated plates worn, must be replaced.
C - Tarnish blue/brown at outer and/or inner area of outer plate: Outer and coated plates overheated and worn, must be replaced.