Sounds like status seeking behavior, the car is not a form of transportation in that case, its a "lifestyle" proclamation to the rest of the world. He wants everyone around him to recognize that he has made it to a point in his life where he can blow cash out his tailpipe if he wants to.
I think thats what the french call nuveaux riche
This goes too far, because it misses the point of peak experiences. Driving a fast car fast is unbelievably fun and exciting. Doing it at the expense of working another year, not paying off debt, etc., may not be as good an idea, but the joy of driving itself is actually a true experience for many people. Putting aside the environmental impact, there is no difference whatsoever between this and my buying a "race" bike so that I can go a little faster in my race group. We both can afford it, and if it has no impact on our financials, so be it.
What gets lost sometimes in this forum is discounting what other people's true "happiness" things are. We presume that fancy dinners are not worth it, because most people don't actually gain much lasting enjoyment from them. But there are some people who truly relish those experiences. Fine. I'm not one of them, but their wanting a fancy dinner is no different than my getting a better than baseline bike because I really enjoy riding a bike fast--it makes me truly happy.
If you ever go to an event where people are tracking their cars, you will meet some of the happiest, most content people on the planet. It's a ridiculously expensive hobby, and not one good for the environment, but the fact that you may not get it doesn't mean that the people doing it aren't truly having a meaningfully happy experience. Like someone climbing a mountain, traveling to a secluded island, etc. What is being factored out of the equation in OP's post is the financial cost--because it either is insignificant, or more importantly, OP's friend has decided it's worth it to him.
We can debate tradeoffs, but this post isn't about tradeoffs. It's about one person doing something he really wants to do, at a cost that for him seems totally worth it. Is your new bike, fancy dinner, trip to climb a mountain, trip to see a foreign country, trip to secluded island any different--if you decide it's worth the cost and it does actually bring you happiness?
Btw, I'm removing the environmental impact in this entire discussion because that raises issues that are almost impossible to control for, and it's not really the main point here. If you're not sure, just substitute in the following: "OP's friend wants to work 2 more months to buy a new race bike so he can ride with the fast group 3-4 times per week, and his finances are otherwise flawless." Where do you come out on that?
P.S. I used to track a fast car. We're now a one-car family, and I typically take metro, ride the bike, walk, and would never buy an expensive (and likely, any) car again. But I recall how much fun it was.