I have a January, 2006 built Calais V6 and it has all the niceties that existed in the earlier 2005 Calais. The reversing mirrors are included as is the glove-box light, active select for the 5 speed transmission, power operated front seats etc.
The main difference is that 2006 build vehicles were down 3 kw in engine power due to compliance with the later Euro emission specs (Euro 3 I think) hence the reason why Holden changed the engine covers from the ones that had "Alloytec 190" moulded into them and replaced them with plain covers that just had "Alloytec". Also the standard wheel/tyre combination was 17" x 8" rims fitted with 225x50x17 tyres.
The so-called leather trimmed seats are actually leather only on the faces where you sit and lean back. All other faces (sides, headrests etc are an imitation leather made out of vinyl with a webbed cloth backing. It's a pretty good imitation to the undiscerning eye but still it's a major cost cutter for GMH which puts it on a path of pissing-off many previously loyal Holden owners like myself.