Several of the Brisbane guys have been seeking affordable towbars for both 156 & 159 sedans& wagons.
Look what I found!
http://www.ebay.com.au/itm/EURO-TOWBAR-Bar-Only-Alfa-Romeo-156-Sedan-Wagon-1999-2006-1600-60kg-/331810276393?_trksid=p2141725.m3641.l6368
( I just know everyone is gonna tell me "yeah yeah . . .old news Baz)
$265.00 BRAND NEW.
And as for wiring, there is a full guide in the back of your Owners Manual of how to hook em up!
Enjoy.
Check Six
Baz