Here's my opinion on this: if my daughter is doing well and helping herself- doing what she should, either working, going to school, whatever, then I don't mind doing some things to help her. For example, if she is in a good place and her car breaks down I am happy to pay half because she is doing what she needs to do, and this is something that will make her life a bit easier. When she is in a bad space- forget it. If she's not working or going to school, if she's drinking again and running around, if she's not maintaining housing I won't help her financially at all. To me, if your son is living in his car, that's his choice. If he really wants to get housing and have access to a shower he will save his earnings and figure it out. My daughter bounced around for awhile- homeless with a small child- and when she got sick of it she got a decent job, got on housing assistance and found a place to live. I guess I sort of live by the "reap what you sow" motto. If she's really trying to make her life better I don't mind giving her a hand, but if she's not then she's on her own. I feel like helping her when she's working and/or going to school is an investment in her future. Helping her when she's doing nothing is enabling that lifestyle and throwing money into an abyss, it's never ending.
That's how I feel. My son is doing things to help himself (even while making unwise choices). But even at his best he's not much of a money manager. A couple of months ago he was visiting and didn't have enough money for gas to get back home. I loaned him the $15 (in the past I probably would have just given it to him). Since then he has not even mentioned that $15 let alone tried to repay it. So I won't loan him anything for the foreseeable future. Not long ago I went with him and a friend to an out of town event. The friend was dead broke and my son had about $20 in his pocket. He didn't realize that he would have to pay for parking (the same event in past years had free parking) so when I got hungry I bought sandwiches and soda for the three of us at the grocery store and we had a little picnic, and then I put gas in his car to get the friend and I back to Daytona and my son to St. Augustine. I'm not sure I would have done that if an empty gas tank meant I wouldn't be able to get home myself. i.e., if my son said "I need gas money, I'm stranded" and I was safely at home I would have let him work that out on his own. (Maybe lol)
And to what you said, I will help my son in small ways (never again anything involving hundreds or thousands or dollars) as long as he is working towards providing a life for himself, which he seems to be doing. But although he's doing the right things to overcome the bad situation he's gotten himself in, I don't think I can be a participant in that. He alone made the decision to relapse and he alone made the decision to quit his job. I'm proud to see him working through all the consequences those two poor choices entails and I've told him so, but I won't bail him out. If he can bail himself out and get back on higher ground I think he will be very proud of what he can do on his own and keep pushing himself forward. At least that's my prayer.