Both my children drive cars that we handed down to them, but they pay the insurance, etc. They both pay their renter’s insurance. The oldest is severly underpaid in an otherwise good job; sometimes we pay for the difference between a red-eye and a better flight to put my mind at ease but I silently curse his cheapskate boss. But we don’t pay those sorts of things unless they ask for help, and they are always grateful and we always negiotiate the amount. Parenting youngish adults, I find saying “how can I help you?” and then listening gets us all better results. I want them to struggle a little, but know that if things are desperate, we will help as they decide what that means.
I had a lot of ideas about what I would, and wouldn’t do for my new grads/new adults. That whole “life is what happens while you’re making other plans” has certainly applied to us. Faced with them driving around in horrifically unreliable cars, or buying ourselves a used car a bit ahead of schedule so we can give them our 4-yr old reliable car wasn’t exactly a plan but it made more sense than any alternative.