The yellow car in your post, skyguy85, is a photochop of a combination of things.
The original and first is the Solstice.
Then, the Vauxhall VX Lightning, later just called the Vauxhall VX with the second showcar built and shown at 2004 NAIAS (along with the Nomad, Curve, and "productionized" Solstice).
Then, the SKY was designed, using the VX as a basis, melding it to the Kappa platform - but with "future" Saturn & (unbeknownst to us semi-common) Opel features.
The Opel is the SKY RedLine with fascias to fit euro license plates and Opel 'lightning bolt' badges (called, in German, a "blitz") in place of the Saturn badges. I'm sure there are some other minor differences for Euro market, but that's my understanding.
I'm sure they intended to have an Opel following very closely after the SKY, so incorporating Opel features into the design of the SKY was very smart.