I bought a 54000 mile 2001 2.2 Z3 back in April. Condition is pretty much perfect. Not even any rattles (though it does have a "characterful" squeaky steering wheel). It's a very well made car no matter what certain Internet "personalities" will tell you. Like any BMW it just comes down to how much it was loved and cared for in the past.
I was one of those guys that filed themselves under the "I will never buy a convertible" label. If you are currently self filed under this label, just try it. It's a whole new world. I'm putting it down to "roadster" instead of convertible. So try a "roadster". It changes your perspective on all sorts of things.
The little m54 2.2 spins like a sewing machine, makes some glorious sounds, pops and crackles and makes you feel like you are going really fast even though you aren't. For context it's about the same pace as a modern MX5 / Miata.
And that's the thing about this car. The gearing is so short you are changing into 5th at 80km/h (50mph) when cruising. And at that speed you genuinely believe you are going very quickly.
It's such an analogue experience as well as being so connected to the elements. It makes you question how much more enjoyment you get from today's super capable insulated cars. Isn't the point of driving just to have fun and feel like you are going fast?
I also think the car has aged spectacularly well and looks better now then when it was released.
Any other Z3 owners on here please chime in!
Finally, this video is nicely produced and pretty much exactly matches my thoughts.