I say..your 30's why?
Most likly you have had a job(career) for awhile and therefore have money to blow on cars and car parts.
You've got a house(not your parents) with a garage.
Your in some kinda of serious relationship with the opposite sex. Why does that matter? Because then when your car is on jack stands in your garage and your waiting for the parts you ordered to show up. You can drive your wifes/husands/boyfriend/girlfriends car until your parts are delivered.
And if keep yourself in shape you can still pass for 20 something if you have to or want to
