This going to sound like a sad country music song, but I will list it all see you say.
1998 A6, 160,000 miles.
My speedo has been boucing for the last two weeks when I get around 70+ MPH. Then it got worse and two days ago died. No speedo and the odometer is not turning. Then the next day the check engine light came on. Car seemed to be running just a little rough.
Today power steering is a little stiffer than normal. No leakage anywhere. No noise. Fluid is 80k miles old, but seems OK, not burned or dirty.
The fuel gauge is now boucing a little.

Are any of these connected? If not then any guesses on each item. Thanks.

The code is P0501, transmission speedometer sensor.

 

Codes.......COdes......CODES!!!! Sorry but no one can really start to help you out with any of these questions without posting fault codes. Best guess for the bouncing gauges is the instrument cluster is pulling a TT failure on you.