So last week, something in my clutch went out when I was driving home from work. I was shifting from second to third gear and it kinda sounded like it was in neutral, but i still could drive it a bit. Also the clutch stuck to the floor and I had to pull over and pull it back up. I had to shift the car into first gear while the car was off so i could at least get it back home because i couldn't shift it while the car was on. The clutch also has little to no resistance when I press it down. It will come back up though after i press it now. And the clutch pedal vibrates when the car is on. You cant see it but you could feel it. Its a 1997 A4 2.8 quattro car

 

I have an auto so I know nothing about clutches. I think Audi uses a hydraulic clutch and you could have a leak or vacuum issue. I saw this when I Googled that might be helpful:

https://www.yourmechanic.com/article...vin-sunderland