Jerome - don't even be subtle with him. You need to explain the facts of life and what he got from you while growing up to where he is today. Sometimes kids lose 'perspective' on what mom and dad did for them. While he may get upset for a while, he will probably think about what he did and have an "awakening". If not - well then limit or deny him use of the garage. If he is asking you to pay for parts, then do it - but labor, remind him how many times you took him to sports or other activities and you waited. And waited - I know I did. Tough love - not really, but sometimes they need a life's reminder.