I myself probably wouldn't do that. Was in a similar situation once, and didn't go there. I focused on my own situation, and own well-being.
I would just go enjoy the car, and have a blast. You'll get enough enjoyment out of her troubles with maintaining and repairing the 525, if she decides to keep it.
If you do decide to go there (and it's your call), that's OK. I would think twice before putting together a scenario that involves your children, though. I took the "high road" from Day One with my children, and now, 11 years later, I am happy that I did.
PS-I loved the way you wrote it up, also. You did a good job of making it humorous.