I too didnt find my 335i exciting enough. It sure was a nice car and grabbed peoples attention even more then S2k (fully loaded e92 with real nice color combo). Step up from S2k would be Cayman S or 2007+ Boxster S but thats a bit more expensive and less reliable. I wanted something reliable and cheap to fix. Next car hopefully will be Cayman S.
Surprisingly many older people are S2k fans as well and picking one up from them is safe. I got mine with 30k miles from 65 year old couple who babied their car like crazy.
Trunk space might be an issue since its obviously not 3-series, but hey....i am carrying an 8ft box to fedex today