Knowing he has a DUI and would rather spend his money playing than getting set up in life only makes me feel more of the same, actually. He’s young, for sure, but unless he has to face some consequences that are directly related to his actions (like having to pay a loan, or having to pay a lawyer), he will probably not learn that actions have consequences. These are the sorts of kids who make me think that a mandatory year of service to the community is a good idea. The world is not all about them.
Perhaps you feel like you didn’t parent them then, so you have to parent them now? However, I’m not sure he’s at a formative age (like kids are) when parenting can help. He’s discovering the world on his own, semi-adult terms, and that might do the teaching if it’s allowed to do so.
No matter how a kid grows up, there comes a time when they have to use that experience to live as an adult. (I came from a single-parent, welfare, abusive home myself.) Once they grow up, though, you are no longer totally responsible for their actions. You didn’t make him drive drunk, that was a choice he made. Even if he made it because he didn’t learn as a kid that drinking and driving is bad, he must learn it now – or he will keep doing it, and maybe one day die in a crash, and God forbid, take someone in the other car with him.
Perhaps, if you want to actually help him rather than just shelter him, there are other things you can do. Does he need to learn how to set up a bank account or a budget? Don’t just do it for him, show him how. Maybe he needs help writing a resumé to find another job on his own? The economy is in the gutter now, but when it picks up, finding another job on his own will be a real life lesson.
One thing to remember. Whatever choices they make now, you are not responsible. If you believe you are, at least for now, how old will they have to be before you can acknowledge that they are making their own choices that you cannot control?