Thought I would update this a bit as my search continues. I have gotten a chance to drive a few of the models I am considering, and frankly surprised myself with results.
Drove a base Z3 from a local dealership. I liked the car and had plenty of room inside. Good power and handling, love the bulging rear fenders in the rearview mirror. The pedals were horrid for me, seemed much to close together. I was wearing my work boots which are heavy and don't offer much tactile feel, but my foot constantly pushed the brake and gas pedal at the same time. I seem to have an unusual preference for cars with wide tires and wide hips (rear fenders). Jaguar XJRs, Z3Ms, Porsche 930s and even the rear flares on the new Corvettes draw me like a moth to a flame.
Tried to buy this Z3M, but the guy sold it just a few hours before I could commit to the deal. Had a hardtop and 126,000 miles for $11,500
After missing that deal I went and looked at a 2002 Mustang GT/4.6/5sp. I was really nice looking bright yellow and chrome wheels, but had been driven pretty hard, bald back tires and a check engine light. The loudness of the Borla exhaust made me feel my age, it sounded nice, but as RPMs increased it started to sound like a glasspack exhaust and the resonance would get tiresome quickly. The ride was pretty harsh, and the car had a ton of cowl shake.
Saturday I went and drove a 2002 S2000. To be honest I went with a bad attitude thinking I wouldn't even like the car. I was absolutely floored by how much I did like it. It was a bit cramped inside, but I could live with it. Took me only about 30 seconds to get used to the clutch operation, loved the short throw shifter and the handling was superb. All things considered it was a very easy car to drive, just puttering around it was fine, and the guy was cool about letting me really run the RPMs up and get a feel for how fast the car really was. We dropped the top and got the heater cranked and even at 40 degrees out, it was just fine to cruise in with the top down. Only complaints are the ride was pretty harsh and the engine a bit raspy. Could probably buy this for slightly under $11,000 with 92000 miles.
After that I went and drove a base Boxster at a local dealership. I really liked that too, the ride was more supple than the Honda, and it was just as easy to drive. The motor was quiet and smooth, while having more than enough power to make the car feel sporty, I am sure the "S" model feels even better. Interior seemed to be roomier, and the car overall just seemed to be much nicer, and of course priced much higher. The dealership had the car priced very high, but there are better deals around.
Still shopping around, but the S2000 seems like an OK buy if nothing better comes up.