A few weeks ago, I installed a gasoline direct injection (GDI) system in my Lupo TDI (AMF, manufactured in 2001). I used the following instructions:
http://www.lupoclub.de/board/thread.php?threadid=17155&boardid=3
While it's actually designed for the Polo, it largely corresponds to the Lupo (and probably the Arosa) in its essential aspects.
Bosch sent me a wiring diagram from the ESI-Tronic system upon request. It was 17 pages long. The part numbers in the manual didn't quite match, but at least the login information was correct.
I can't be certain whether it works the same way on your Arosa.
This whole thing took me a total of 12 hours of work, so don't start it right before an important deadline.
