Well I was comtemplating buying a 2004 G35 last Autum before I brought my Audi A4 1.8T Ultra Sport.
I could've got the G35 for less than I paid for the Audi, the dealer was willing to do whatever deal it took, plus Infinity was having dealer incentives which Audi never does.
The astethics of the G35 were not there for me. I did not like the front end esp.
Also the interior of the G35 looks and feels cheap to me (I understand that they improved on this for the 2005 and later models)
For fit and finish Audi, as well as other German automobiles are tops. Say whay you want about Audi, when you sit in one you know why you spent so much money.
I understand there is a movement afoot in the auto industry to stop making manual transmissions in favor of using technologies like Tiptronic.
Reason being they aren't enough manual drivers on the road now and kids find it hard to pick up (least in the states anyway)
Pitty really as it is much more fun to drive.
You will have to think of the safety factors when considering whether or not to dump the manual transmission for your wife.
If she is willing to or already has learned how to use it and is comfortable with it I would keep the Audi.
You might want to check over at
Audi World or
AudiZine for opinions from other Audi owners as many of us did consider the G35