2002 Quattro. 60K miles.
Recently, when I use the high beams to do a quick flash, the stereo mutes for a split second, and both the speedo and tach needles drop to 0, sit for half of a second, and then roll back up to where they belong (current speed, etc)

Oh yeah, and it doesn't happen all of the time.

Any ideas?

 

ground problem ensure all grounds are secure and clean