One of these?Got to: http://www.metalnerd.comsearch in Specialty Bits and Drivers - $23 USrt MN3001 - Specialty Socket for Triangular Head Bolts
Hans/emiata has itCheapI bought one from himJon
How about this one?http://www.ecstuning.com/Volkswagen-Golf_I-Convertible-Diesel/Tools/Hand_Tools/ES258694/Little on the expensive side. I think I would grind out a snap on for that price.
Among the things I've bought from him - the exhaust clamp release tool (at manifold), sells for $45-$90 elsewhere. I paid like $15 from him for an identical one I paid about $75 elsewhereNow I have 2, making it easier to installJon