Great determination.Ok,For those XU1 purists/rivet counters like me or for those who may be interested, I have found that factory finish under rear guards is the anti chip wrinkle tar finish then sprayed over with the exact same colour as my boot (Adelaide May 72 car - gun metal/blue type colour). Not sure why Holden would use this colour and not black under guards but suspect just to get rid of it. Have scrubbed under both rear guards with truck wash only (no spirits) and this is the finish I am presented with and I believe its as it came from the factory. Shit job scrubbing under here but 47 years of road grime and its never ever going to be driven in the wet or on dirt roads again in my life so I think its worth it.
Very interesting result.
