My younger brother is planning to walk out?

hey all
my brother is going to become 18 in a few weeks. hes in his senior year. our parents are very controlling and this leaves him pretty bitter. the folks always tell me to drive him wherever [be it school, to see his friends, off to football etc] and he has a very strict curfew of 6 pm on weekends/holidays, and no going out on school days. girlfriends are out of question, and hes forced to basically all family events [ie thanksgiving at grandmas], and to church on sundays. this has left him a rebel, and for whatever reason, he has gotten suspended a few times. he and i are pretty close, and he tells me that he plans to leave the moment he finishes high school.
tbh i was in his exact situation a few years ago. my parents kept me in a cage till i was in college, and i thought i was free after i graduated from school. but then, real life dawned. i ate at shelters, worked as a burger flipper at mcdonalds, and was kicked out for not paying rent more then once. real life was tough, and i realised it was that much easier to live with my parents, accepting their rules and their money. my fathers biggest rule is that if i want to live on his money, i follow his rules. its pretty simple and once it dawned on me how lucky i was that my parents still payed for everything for me, i never questioned them twice. many of my friends are sceptical – im doing a masters degree while getting an allowance from my parents and not being allowed to have a girlfriend, but i feel that its me whose gonna suffer if i were to listen to my friends’ advice and vouch for freedom instead of family.
how can i convince him to do the same? my parents will definitely not pay for his college tuition if he leaves, but he is young and he can’t understand in what sort of position he will be in on his own.