Can't access the link from here, but no one has to take a blogger's advice 100%. An important detail is becoming fully conscious of your spending choices. MMM rants at length about big, luxurious cars. However, he is in the prime of life and blessed with good health (slight assumption here). He also lives in a relatively low population density area.
I live a few miles outside DC. The drivers here are insane. Driving a Honda Fit or similar I consider an unnecessary risk if I can reasonably afford otherwise. If I'm in an accident, it will probably be some idiot texting while "driving" their Suburban. Small cars do not win in that scenario. I drive a Subaru in order to have a snowball's chance if that does happen. I'm not getting a Suburban; that is more vehicle than I need anytime soon. It was a choice that DH and I discussed and did consciously. While a WRX would have been lots of fun, it was not justifiable. We could have spent more in other areas, but we don't.
My MIL drives the sort of StatusMobile derided on this site. She has some major joint issues, so getting a more "spartan" ride is a very different value proposition for her than it would be for MMM, who is still quite spry. Leg/knee airbags have not reached middle-market cars yet, as far as I am aware. MIL paid cash for the thing and she has all her other financial ducks in a row. My base model Subaru was less than half the cost of her car, and its seats do bother some people's backs. MIL is bothered a lot more. Hers was also conscious spending. Yes there's lots of bells and whistles that she likes, too, and it's a nice and pretty car. But she isn't leasing it to keep up with the Joneses. The Joneses can go hang as far as she is concerned.
Someone might tell me I spend "too much" on food because you see lamb or lox in my fridge. You are welcome to your own opinion, but you will not be welcome to dinner with that attitude. :)
Facing the line items in your budget where you may have screwed up is an uncomfortable feeling. Some people may be willing to buy a smaller house if they can drive nicer cars. Others might be willing to trim clothing budgets to free up food/entertainment money, or vice versa. Others may be content with a week in Branson rather than an overseas trip. If you have credit card debt, if you're behind on your retirement savings, or have gobs of student loans, you need to take a harder look at your budget. And that IS uncomfortable. But if your coworker doesn't prioritize travel and does prioritize a slightly roomier car... why feel defensive over different priorities?
...so long as your other ducks are in a row. If they aren't, you SHOULD feel uncomfortable- but the car might not be the first place you economize. Just start the process according to what works best in one's own case.