Audi A3 8L: MFA Retrofit Installation Possible?

A colleague at work has an Audi A3, type 8L.
Baujahr 2001, MKB ASV (81 KW) erstanden. The car has...
keine MFA (oder wie das bei Audi heisst). Is a.
Is it possible to retrofit it?
The search led me to www.kfz-kabelbaum.de.
where wiring harnesses for this project are available.
What does that mean? Is a different instrument cluster required?

The only thing really missing is the average consumption display - perhaps.
There is also a partial solution.
Thank you for the responses.

Greetings, Klaus.

G3 AFN 190 km