Buying a sports car when you get older isn't a midlife crisis . . . it just means you've gotten to the point where you can afford it and you've come to the realization that life's too short to drive a Camry.
A midlife crisis is leaving your wife to chase women 20 years younger than you. I had a partner who did that. Didn't really work out for him. He should've taken into consideration the fact that he looks a lot like Herman Munster.