How much of your net worth would you spend on a car in the future?

I'd say a sensible amount to spend is 20% of your net worth on the FULL price of a new car. So if you're financing you can afford much better cars.

£100 000: Nothing.
£500 000: Between 10 and 20 percent.
£1 000 000: 10 percent at most.

probs more than my net worth, then file for bankruptcy

what about 250k?......

40 percent, at most. I'm trying to keep the absolute amount in each case restricted to about £100 000. I don't think there's much point spending more than that on a car, even if I was stinking rich.

um... Actually i'd rather invest (stocks, watches(jewellery), land), wait a few (5) years (by then there will be better cars out, maybe even cheaper and the quality even better), sell the investments (if you were handling stocks, that would be a different story), and buy a nice car you can actually afford buying, cause bare in mind; The car will min. lose about 50% of its monetary value as soon as you sign the contract (So you might want a decent amount of cash back for when you sell it), and the amount of gas it will consume should be affordable at that point in life and in future.

But to answer your question Bill_Gates, people sometimes make irrational choices they will certainly regret in the future, they do what makes them happy
Other than that the car could just be a "job-car", one you would get provided with by doing a job for a company. For example, instead of payment you get to drive a brand new car for a year.

yeah i get that but this is the assumption you've made your desired sum and how much of it would you spend on a car? lol % wise.

All of it