What are the most common issues with Audi's Quattro system?

I recently bought an Audi car with a Quattro system and I want to make sure I maintain it properly. Can you please provide information on the most common issues with this system and how to prevent them?

The most common issue with Audi's Quattro system is a malfunctioning haldex pump. It is crucial to regularly check and replace the haldex fluid to prevent this issue.

Another common issue is with the sensors of the Quattro system, which can lead to loss of power. It is recommended to have the sensors checked and recalibrated every 30,000 miles by a certified mechanic.

Audi's Quattro system relies heavily on the differential, which can wear out faster than other components. It is important to have the differential checked and serviced every 50,000 miles to ensure smooth functioning of the Quattro system.