Just 4000 kms after the 100k kilometre service, my wife's 3.0D transmission has failed. It had recently started to become a little clunky on downshifts. This was only intermittent.The local auto transmission shop (the nearest dealer is 200 kms away) dropped the pan and it had a lot of metal filings in it. I have now been informed that it need a complete rebuild costing AUD 6200! He advised me that the gearbox was a GM box and that he would be doing some modifications (as devised by some company in the US - the name escapes me) to make it 'better' than new.He said that they are fitting this gearbox to new Holden Commodores and that GM Holden are just replacing the gearboxes as they are all under warranty. Now I have read all the should I or shouldn't I change the 'lifetime' transmission oil posts, but my question is....if this gearbox is clearly not GM's finest engineering triumph, why did BMW and indeed Holden use it??