I guess MMM has the right to spend his excess money in any way he pleases. I for one am happy that he bought an electric car and I presume he is going to drive that thing into the ground.
Things like 'don't drive a clown car' are really great rules when working towards FI, if you are FI and a car purchase doesn't change that then why not treat yourself?
Especially if it is more environmentally friendly, can be charged from PV systems for free.
One problem is that even an EV is very bad for the environment. Just because it has zero emissions does not mean it did not take considerable resources and cause considerable pollution for its manufacture, maintenance, transport, sale, marketing, etc. And just because you can charge it "for free" from a solar array doesn't mean that solar array didn't also take considerable resources and create considerable pollution during its creation.
If your argument against cars for "fun" is environmental, you have no good options. You only have bad options, and worse options. EVs are a considerable improvement, but they are no where near "guilt free" cars when it comes to caring for the environment.
No car is guilt-free. No house is guilt free, nothing you can buy in a supermarket is guilt-free. We have an impact on this planet if we live on it. It is almost impossible to avoid some sort of environmental impact no matter what you do.
If we wish to live in a world with electricity, warm water and transportation then there will be waste no matter what we do.
And as you said the EV is probably the best choice right now when it comes to transportation. If you gave up transportation that would be better, but even a bicycle requires energy to manufacture.
However with proper recycling an EV represents the current "state of the art" when it comes to minimal impact on the world. Even accounting for battery production and lithium extraction.
Current PV systems are estimated to be net-energy/co2 positive after 3 years of service. So there is still 22-27 years of life in the panels where they produce energy for free. Overall PV and wind-energy er net-energy positive and hence very good for the environment.
If you live in a place where your PV power offsets coal power then the math looks even better.
And since an EV allows you to utilize your PV system to a much higher degree this becomes even more attractive for both the wallet and the environment. Overall a win-win type scenario.