Buying a Tesla isn't a great financial move for any of us, generally speaking. It's responsible in other ways, but not so much for our wallets. However, "only about $137 more a month" for 72 months is not an insignificant outlay. I had a loan on a Nissan Frontier when I was younger, and the payments over 5 years for that truck were about $300 per month--you're talking about adding nearly half of that monthly payment for a mere upgrade--again, that is not insignificant. If you were to invest that $137 in an index fund each month over the next 6 years instead, you could end up with about $13,000 in savings based on the historical average return of the S&P 500. Which would turn into $128,000 in 25 years if left in the same fund--a significant boost to your retirement savings.
Most car loans will seem "doable" if you stretch out the payments over 72 months, but (in a normal market) you're putting yourself at high risk for being underwater on that loan for many years, and you'll likely tire of the car before you've got it paid off, which for many people results in rolling the balance into yet another car loan, which means they might still be paying for that LR upgrade in 15 years when they're not even driving the same car.
So your hypothetical options are: 1. invest the money and end up with a hundred grand, or 2. spend the money on a car you probably won't be driving, but might still be paying for, in 6 years.
Did that work, LOL?