sounds like you boiled off the fluid in the slave cylinder. some systems are self bleeding. not sure if ours is or isn't. usually it's shared with the brake fluid. I would check that the brake fluid isn't low.
Good call, Mike. I would support that idea.
How old is the clutch fluid? Is the slave cylinder in a place where engine heat can easily affect it? I haven't looked. On the Gen 1 Caymans, the power steering fluid reservoir was vulnerable to engine heat. Maybe this slave cylinder is becoming that sort of weak point?
Good idea to make sure and specify that the clutch fluid needs to be bled out and changed along with the brake fluid at service time. I've often neglected this working on my own cars. Never really had a problem with boiling clutch fluid, but with this mid-engine car, could it be??? Do we need heat shields? A fan?
BTW... OP, to enjoy a sports car it is not necessary to race off every stop light. Every time you do it, it tears the car up a little bit...and they aren't cheap to fix!. Hit the go-pedal hard, but only.... AFTER the oil temp is up to about 180 and when your left foot is OFF the clutch.
...Remember that all auto journalists are driving someone else's car.
Anytime you are slipping the clutch, you are wearing the clutch lining. When you slip the clutch at high RPMs, you wear it out fast. You need only about 1000 RPMs to smoothly engage the clutch...not more, but 1500 is OK, so long as you're not doing that repeatedly, uphill, in bumper-to-bumper for an hour etc.
When clutch is all the way in, or all the way out, no wear.
Want your clutch to last, like, for-ever? Drive like ME. I always start off at low revs, get the clutch OUT, then accelerate, sometimes hard, but always AFTER the clutch is fully out. Endurance racers know this sort of stuff. Think about the way the car actually works and drive accordingly.
Porsche could put a mondo-sized clutch on these cars and make them drag racers, but they wouldn't be a nice to drive and it would add weight and pedal effort etc.
I have a couple of techniques for avoiding clutch problems when I get stuck in traffic:
1. Leave as much interval as you dare...too much and someone fills the gap, but there is usually a place where you can keep pace with traffic, defend your lane and still leave some room. Find that happy place. When traffic slows, let your interval shrink as the engine braking slows you...no need for the brakes, many times, or the clutch...if you time it well, traffic will start to move again before you tag the car in front. This can be a fun game.
2. Use a gear lower than you need to and use engine braking...clutch still out fully. These cars will creep along at a fairly low pace in 1st gear smoothly at idle or a little above. Keeps airflow going and you aren't constantly slipping the clutch.
3. Hit the "long ball". Don't try to capitalize on every opening in traffic. Choose your battles. If you look beyond the immediate neighbor, analyzing the traffic situation gets to be second nature.
I actually enjoy a nice drive to the city in traffic...but it takes a little discipline to resist the racer instinct in slow traffic. I only "go for it" if I can see that my lane is really slower than the rest of traffic and that there is significant gain to my lane-change...and I won't be discourteous to other drivers.
There is a satisfaction I get from a well-driven trip into/out of the city in my manual Cayman. Not melting the car down is one of the goals, for sure.