2003-2006 or so 911s aren't very expensive, but usually have quite a few miles obviously. Was looking at the boxter S as well, I just wasn't sure about the interior room and lack of a real hard-top. I think you have nailed it with the cayman. Awesomely balanced chassi, and I'm sure it wouldn't take much to make it outperform a 911 in many ways (like bigger anti-sway bars, etc).

Some of the current 911s just make no sense. 911 turbo (covertable especially), quite heavy, AWD system making up for lack of handling at extremes, bested by GT3 if you have the balls to try and take a GT3 to it's limits, but they've had to make it ungodly wide, which looks cool, but it just keeps going over the top IMO. It's cool that they've made so many variations, but that great engine just needs to be flipped onto the other side of the axle, and with modern advancements I think they could take the engine size down a bit and have as much or more power for better milege. At the least it wouldn't require the 10 foot wide rear track and tires, or AWD system, which all eat at mileage.

I still don't want to sound like I hate 911s, I love the styling and the cars in general, but it's time to fold and stop trying to fix the engine placement. If they are really clever they could still engineer some rear trunk space into a mid-engine layout, not that it's all that necessary if you got a trunk on one end and a little cubby-space behind the front seats for a bag or two (not the half-rear seats, I got those now in my current car and it's not like you can take people with you or anything).

I've seen some amazing videos of modded 911 turbos pushing out 1000hp and just killing modded vipers around a track. A car that can handle+HP always wins on a track.