The problem is the opportunity cost. That money you used to splurge on a car is NOT being invested. Having a nice car now could literally cost you hundreds of thousands of dollars of compounded retirement money in missed stock/bond gains.

Let's say for sake of simplicity you spend $500/month on a nice car instead of $200/month on a basic car. The difference of $300/month invested for 30 years at a 6% return is a whopping $292,353.89

IMO a better strategy is to change your values. Becoming the kind of person who doesn't value a nice car could be a very valuable asset.

I don’t see anything wrong with it either. So long as you’re aware of what it costs.