Outside temperature readout

[Tim Gortner <Tim.Gortner@pobox.com>]

My 90QV8's outside temperature readout worked fine when I purchased the 
car 2 years ago, but sometime this summer it changed.  Now it always 
reads about 13 degrees low.  Of course Prestige (the ONLY Audi dealer in 
Denver) says: (1st answer): Need to replace the whole climate control.  
(2nd answer, different guy): Need to replace a sensor which is somewhere 
near the from license plate holder.  Both options are $$, although the 
sensor is $100+-.

Anyone have an idea??