[racer_d]

1) your ad is stale.. you posted back in the summer.. 4 months ago? Folks have seen the car, again and again. Fresh pictures is a start. Re-working the ad-copy may work too.
2) locale -sure you are located on the "www", but someone still has to GET to PA to see the car
3) mileage... 100K+ miles is a hard sell for any boxster. A 2000 S with that mileage is a $15K car. for 4K more, I would swing for an S
4) buyer demographics - at $11k, you are up against "no money down" for a new car or a 7-9% car loan for a 17-22 year old. Someone in a position to pay cash for your car, is likely not attracted to a) mileage and b) "first year production" concerns, whether valid or not. PERCEPTION is more important to a buyer than reality.
The "other" buyer is one who is looking for a nice "base" for a race car.
5) As asked before - why sell? It would seem that at some price point, it is "cheaper" to keep the car than to sell it
6) Time of year.. cold weather is arriving. Heated seats? if not, that hurts too in a cooler climate. Might be better off taking it "off the road" and selling in the spring as "convertible" season comes into play

Just a few thoughts...