Granted this car may be possible if the manufacturers would put the money in, we are getting close to the 1500HP mark in production cars anyhow, but I bet no big manufacturer sees the gain in making incredibly overpowered stealth fighter like cars over the cost of, even just the R&D required to get the cars to those speeds
I compared before with the efforts of the Formula 1, a very estabilished racing league for decades and decades.
Technical evolution there has a purpose, they have (had) a considerable return with advertising and supporters, and so on. Their cars cost millions and millions in development whenever a considerable change has to be made.
Most makers there are having problems with the budget. So yeah, no one would touch this.
So maybe you can answer the questions I asked earlier, since you got the true intent all figured out. Here they are again:
There's no arms race. Sure Hyundai's will be a futuristic F1 open wheel type, and Lamborghini's and Jordan's will be wack at least visually, but so far, no arms race, no 1-uping either.
Hell, I know the Alpine (initial) concepts are from 2012... So either they messaged each other and some decided to race themselves back when GT6 was releasing or again, there's no arms race.
You have the Chaparral with its ablation thrust and this Tomahawk X with its supercharged turbo, hyperaspirated, fast and large V10 engine with a powerful hybrid system. No arms race.
All the other cars so far are "normal". You could say some even follow the Cayenne school of putting sports car engines in normal car bodies.
Vision GT is not losing its purpose or plot, it was meant as a space of 'collaboration between makers and GT to exercise their "visions".'
If you feel designers (and engineers) think of hot wheels cars when they don't have to meet production criterias, that's okay. I'm sure that has been repeated through history outside of GT for many concept cars. Hot Wheels inspire themselves in car designs and concepts after all.