I confirmed with my dealer that the new 2005 G35 sedans and coupes with ATs have a new feature, - the tranny automatically blips the throttle and syncs the next gear when downshifting. This reduces wear on tranny and results in better downshifts when racing thru a road course or your favorite back road.

Anyone hear if older cars like my 2003.5 sedan can be retrofitted with upgrades to tranny? The dealer didn't know and thought it was a totally new tranny, which I'm sure it is not, - software and soleid upgrade more likely.

 

I'm not 100% sure, but my dealer told me (and I believe others have mentioned the same here on G35Driver.com) that the '05 TCU software unfortunately is not backward compatible with the older cars. BTW - the feature you're describing is called "rev matching."