I bought my Spider brand new in June 08' and I love it, just one problem a few hours after each ride it starts to leak coolant. I have replaced the thermostat gasket as well as the head gasket and still have the same results. I can pressure test it (10-12 psi) and it holds just fine, I can drive it all day and no leak, but like I said a few hours after putting it up it leaks coolant from what appears to be either the seam between the head and block or the thermostat gasket.
Any thoughts?

I had the same problem on my 08 sandspider the thermostat gasket was not sealing even after installing a new gasket. I used gasket sealer in addition to the gasket the second time and it has never leaked since.

Thanks, will give that a try (Hate pulling the head if I dont have to.)