Wow.....I am a little suprised but kind of glad at the same time to see this many Solstice owners with the same problem.
I actually purchased my 2007 Soli new in Sept of 2006. Last summer was the first time my coolant light blinked at me. I added a small amount of pre-mixed Dexi-cool and did not have another issue until like 3 days ago. It started popping off and on again and I have been adding coolant every day now since. I have to add it in the mornings before I head out to work and usually again before I leave the office to go home. While it is a simple enough task it is just down right annoying. I see no wet spots under the car after being parked so I do not think it's a leak, but I can get a distinct smell of anti-freeze when the temp reaches over 200.
Taking it in next week and let the dealer see what he can find, although I may try the cap replacement and see if that helps.
Thanks for info peeps!!!!
Polly