reblu,

The Z3 is a nice car. The Xfire will definitely ride smoother. You could probably use the Xfire as a daily driver. I can't say why there are so many low mile units on the market other than an overall change in the market. Z4 sales are down for the past two years. Not because they are not nice cars, I think mainly because people are looking more at practicality than anything else. Sports cars are not exactly practical. BUT, they sure are fun.

I traded a '04 Z4 for my SRT6. The Z4 had about the same level of performance of your Z3 2.8 (mine was the 2.5). It was fine til I started going to track days and being embarrassed by rice rockets.

Got a killer deal on an SRT 6 and jumped on it. I gave up the roadster for a coupe (I missed the top down this spring) but the performance is unreal. If you get a chance, try an SRT6 roadster.

I am very detail oriented and the quality of the Xfire is absolutely tops. Check under the hood, look at the cable runs, interior fit and finish, door hinges, seals etc. It looks, feels and is very solid.

Good luck.