As you can see in my signature, I owned a 03 G35 6MT so I can definitely answer some questions with having come from the same car.
1. You already owned the first year of the G35. Did you notice any major problems? Mine went in for some TSB's but that was it. The 09's in my opinion don't have any reliability problems though they may have some TSB's as they were the first year model. You do get some added features if you go later such as heated outside mirrors and music blue tooth streaming.
Agreed. 09-12 370z are all the same in terms of reliability. There are only few added features on the later models.
2. The visibility isn't any worse than the G. It is a sports car and it does have poorer visibility than a family car. I don't think it is really any worse than the G was though except out the side rear.
I disagree on this one. The visibility IS worse then the g coupe. Especially on the passenger side and the rear. Back up onto the road will be little tricky especially at night. Mine is worse since I have a Nismo and that big spoiler blocks the rear view. But then again, I already get used to and it's no longer an issue for me.
3. Very safe car and the seats are sport seats. They will be a little tighter for a large person (width). I don't buy my cars based upon the occasional passenger though. My wife and I have to be comfortable and that is all I care about. It only has 2 seats after all which is one of the reasons I got the G in March 03. Ordered it in November of 02.
Agreed.
4. I've always thought the Z to be pretty forgiving on the road. It is a sports car but again not much different than the G.
Agreed. I have HKS coilovers on my g and Nismo springs on my Z, they feel about the same on the street.
5. It is louder than the G. One of the ways to reduce weight is to take some of the sound deadening out. You do not have to yell to talk. We take it on long (5 hour or so) trips and are comfortable and not worn out at the end. You can put sound deadening in place with dynomat and other substances.
Agreed. It IS louder then the g. But not like you can't talk in the car. You will get used to.
6. Not a lot of storage in front with either the nav or without the nav. There is storage behind the seats (shelves behind both and a glove box also behind passenger). The trunk holds a lot more than you think. If I go by myself, many times I've put $250 to $300 worth of Costco items in the car. You are better off to have loose items though because of the struts.
Agreed. I don't care about the storage space anyways. I bought this car as a sports car not a family car for road trip or carrying stuff. Extra weight is not allowed in here!
7. Just as reliable as the G. I've had 0 problems with mine. As with ANY car, you may run into problems but I laugh at those that say this is a problem car. You will see posts where someone got a lemon on here but with as many owners there are you don't see many bad posts. Every car forum has the lemon post though including the G.
Agreed. I have 0 issue so far as well.
I didn't need 4 seats anymore and I thought they softened the G too much with the new model thus my switch to the Z from the G. You will get more looks than the G as the car is more aggressive looking and there are not many of them out there.