When I was a graduate student, I had bought a brand new Honda Accord, whereas my professor, a world renown scientist, used to drive 1990's Toyota. That was one of the most valuable life lessons I have learned in my life:
It really doesn't matter what you drive in your life than how you drive your life.
However, if you are filthy rich and still want to upgrade (than donate some of your money for children's welfare in Nepal), then I would recommend you to buy Tesla. Why the heck do you want to settle for mediocrity in life?