Now that my M3 plan imploded...
What about this?
https://bringatrailer.com/listing/2000-bmw-m5-32/
I would need to do much reading to understand what I am getting into with an E39 M5 but I'd only drive it a 3-5k miles per year. It's bound to hold its value well, no?
The lure of Imola is strong.