All you need to be able to afford a 100k car is 100k in the bank. The question is more whether it's a good idea, and the answer to that is almost always no when it comes to expensive luxury items unless you think you've exhausted potential for having more fun for the same money (that's a lot of fancy vacations, for instance, or a lot of months rent in the event of an unexpected layoff). But only you know what you value so it's hard for someone else to tell you it's definitely not worth it.

As to how sensible a purchase it would be, that depends how much you spend on the rest of your life - housing, food, health insurance, taxes, etc - and your circumstances, eg do you have any dependents / is your job completely stable (are you 99% certain you will be earning this much or more for the next five years?) / how much do you have in savings / do you think you might have any big life events in your medium term (career change / starting a family / buying a house / moving abroad / etc). I can't really envisage a scenario where spending the entirety of your annual salary on a depreciating and expensive-to-maintain luxury is anything other than foolish, but depending on the above it might change towards "lol that was pretty dumb" instead of "holy sh*t he's completely ruined his future for no reason"