I think the NW should not be the only factor when considering whether to buy a car. For us, we considered our passive income as well.

When we were younger (in our early 40s), it will take 3 years of passive income accumulation to fully pay in cash for a mass market jap car. Now, our passive income every year can afford us a brand new mass market jap car.

If we had wanted the E200 or BMW320, it will take us 1.5 years to 2 years of passive income accumulation to pay in full for a new car.

My advice is to build up your wealth first which in turn will allow you to build up a stream of passive income. With that, splurging on things you desire (including that BMW or E200) will be more rewarding, less painful and that will not hurt your retirement plans.