I recently aquired a decent looking S500. not ragged out, with 127k miles.
It has myriad problems:
1- runs fine, 'till it gets up to operating temp, then it won't idle, If you let it die it won't start again (untill it's cooled). Flooded. If you keep it running at several hundred RPM above idle, it will run 'till it runs outta gas.
2- Radio volume is not reliably controlable, turn the knob and mabe it will work, then mabe it will go to full, or to none. Rear speakers are toast.
3- rear headrest won't work, but you can hear the motors run.
4- fuel pump makes an awful racket.
5- HVAC blower doesn't work, (siezed up)
6- I think I bought myself a flood car.
7- It's been sitting for more than a few months.
8- Airplanes are less expensive to work on.