Yes I agree, my brother was under 25 when he got married and rented a car for his honeymoon.
So young.
There are car rentals that rent to people 21 and up if you are wiling to pay a fee.
Acadia in Maine is fun. I've flown into Boston and Montreal- Boston is quicker, but I like Montreal.
I am not willing to pay a fee. Too poor for that crap.