The Nissan Z (whether the upcoming new car or the previous generation 370Z) is a very different type of car than the Stinger. The Z is a strictly 2-passenger sports car, the Stinger a 4 passenger near-luxury, performance-oriented GT sports sedan. I think they would make a very complimentary pair in the garage.
The 370Z is an ironic story. So many car enthusiasts whined about wanting a simple, old-school, affordable, pure sports car, with a naturally aspirated engine, manual transmission, and devoid of most of the cosmetic fripperies so many new cars are loaded down with. Nissan did the world of car enthusiasts a favor by continuing to sell the 370Z, and instead people whined about how it was 'old', and had an 'out of date infotainment system'.
If you're driving a real sports car, your 'infotainment' should be the feel of the car, the sound of the engine, and the pure fun of the driving experience. A colorful infotainment graphical interface shouldn't be that high on the list. If it is, you probably should look for a different kind of car.
Nissan has done the car geek world another favor by introducing a refreshed Z. I for one am glad it's based on the previous 370Z platform. So it's 'old'. So what? The real question is, is it still relevant? To that I think the answer is a resounding yes. The Z platform still has attractive and competitive weight, torsional rigidity, and basic suspension design. It might not be 'state of the art' for a pure track/race car, but realistically, how many people live on the track? For most drivers, what's relevant is how it feels on the street, not shaving tenths of a second off Nurburgring lap times. As the saying goes, if it ain't broke, don't fix it.
Nissan has addressed most of the things whiners carped about. The interior is refreshed with higher quality materials. Seemingly most importantly to the complainers, the infotainment system now has a nice, big, colorful, modern screen and interface. The engine is now the turbo 3.0, I personally would prefer the previous generation N/A 3.7 for its more linear power output, but the whole world is going turbo these days for the perceived fuel mileage benefits (at least the way turbos game the EPA rating system), and it does have more power than the previous engine.
Styling is purely personal and subjective, but I think the Z's lines are smooth, svelte, and timeless. They captured the spirit of the original 240Z with a design that will probably still look good in 30 years. You can't say that about the over-wrought, contrived, somewhat distended semi-bloated BMW-in-drag Supra.
The result is a 400 hp, manual transmission, rear-drive sports car that will probably sell for around $40k (maybe low-mid $40's out the door). That, my friends, is a bargain these days.
What's the competition? The Supra 4 cylinder is even more expensive, has less power, and most importantly, doesn't have a manual transmission. The Mustang GT on paper can be had for a similar price, but only in a stripped-down version and with significantly lower build quality and reliability. The Corvette is more than double the price, and even that can't be had with a manual anymore. The BRZ/86 is a great car (I own one), but with about half the power, is in a different class.
The sports car segment has been shrinking for years as people increasingly flock in lemming-like droves to SUV/CUV boxes. Outside of Mazda and the Miata, it's hard for any manufacturer to make money with a sports car these days. We should thank Nissan, and Subaru/Toyota as well, for letting just a little passion come into the decision-making process instead of bean counters run the show, and making the Z and the BRZ/86 at all.
We are driving (no pun intended) inexorably to a soulless, bland, anodyne, boring future of battery electric boxes and autonomous transportation pods. The Z and BRZ/86 are probably the last of their kind. It's unlikely there will be new generations after these. Once the internal combustion engine, and especially small, affordable, manual transmission sports cars are gone, they won't be back. It's last call for sports cars. Appreciate and enjoy them now while we can.