Hmmm. Where do I start. I guess this is going to be long as hell...
Re: Comparing apples to oranges
I was more or less comparing sports cars with a similar price range. Take the G37 out and insert the 350Z and the Z4 looks even worse as a purchase to me.
That's because you're only looking at the features and specs that make your argument look good and ignoring the advantages a Z4 (or any BMW) brings to the table.
For one, you really need an apples to apples comparison, instead cherry-picking what data to show and stacking the field. Conceptually, the best car to compare to a 350Z would be a $40,700 Z4 3.0si Coupe (or price-wise, a $34,900 135i Coupe). We could delve into the mind-numbing minutia of going feature for feature, but I think the basic, fundamental differences of comparing a BMW to a Nissan lies in engineering and refinement, especially with the Z4.
Z4 is based on a much stiffer unit body than the 350Z. (32,000Nm/degree, stiffer than Cayman, almost as stiff as 997) You can tell as soon as you drive one (which I'm going to presume you haven't). BMW also spends a lot more money and engineering in NVH control and 'perceived quality' of all the switch gear and primary controls. A very obvious reminder of this is the engines. The VQ is powerful and has a lot of torque, but is coarse, harsh and buzzy at high revs. Comparatively, the Z4's N52 is utterly smooth even at redline.
Second, the BMW, through more extensive use of high-strength steel and aluminum (including the hood) weighs ~260 lbs. lighter than a Z Touring (3,108 vs. 3,376). It also has better weight distribution (50/50 vs. 53/47). And it has more interior passenger space and cargo room as well.
Don't forget that all new BMWs come with free maintenance. Free oil changes, free inspections, wiper blades, etc. Further reducing the cost of ownership. Also, most dealers will put you in a free (BMW) loaner car while you get your (free) work done. I've also had a Nissan before I can tell that NONE of that happens at a Nissan dealership.
So do all these things make the Z4 Coupe a better sports car than a 350Z? It depends on what your priorities are. There's no argument from me that on paper, the 350Z is a very good car and a great value. But the only advantages it has against something like the Z4 is price and horsepower. If you want something more sophisticated and better built, then you might want the BMW.
This all goes back to the steak thing. Seriously, I know you've seen it. But you keep ignoring it. I guess your silence on the matter is the best proof that it's a good argument.
Re: Shifting standards around to suit the argument
The M coupe would be much more expensive for not that much more performance. They both do 0-60 in around 5.0s flat. (which again I point out is meaningless) And yes the Z4 M handles good--but so does the 350Z. A Nismo-spec Z versus a Z4 M would be a more close comparison--which would have the 350Z ahead me thinks.
You seemed to build your first argument around the fact that you get more performance from the 350Z for the same money. Now that you're comparing the Z against a better performing car, you want play down the performance difference.
So from where I'm standing, it looks like you are flip-flopping your standards of judgment to suit the car you like. Not very objective.
Re: Interiors
The interior of that BMW while better than the 350Z--isn't as good as you think it is. Looks good, but doesn't feel as it should from a German car.
The point is that's it's way better than the 350Z's interior, isn't it?

This is another example of changing things around to suit the argument. Be fair and objective for a moment. It's better than the SLK's interior, about on par with the Boxster and not quite as good as the TT's. It's nothing special; average for the class. But still far, far better than the Z's.
Re: Why we should stick to talk about cars instead of people
But when I consider an Infiniti just as "luxurious" as a BMW does make me in error? It seems like people are buying BMW's JUST because they are and not because of any precieved or actual luxury.
It irritates me when I read something like this. It's not because of your thinking Infinitis are as "luxurious" as BMWs, but because you assume that because that anyone who doesn't share your opinion has made an error in judgment.
Why do you like Audis and Benzs? All the, "is it worth the money" arguments you made can also be applied to them as well. But for some reason, this "worth it?" rule seems to only apply to a premium brand you don't like. How convenient.
RE: Wait. What?
I mean Mercedes has more luxury than BMW--but people won't admit it. I understand brand loyalty, I just don't understand sometimes the huge price difference for the little extra you may or may not get. ?
Well first, that's debatable.
And second... What?? What the hell does Mercedes have to do with this? Benzs are
just as expensive, if not
more expensive than BMWs. Like I said earlier, every "worth it?" question applied to BMW, you can apply to a Merc.
But somehow MB and Audi are impervious to this type of scrutiny. Why?
I think your bias is way obvious.
M