I believe the Vauxhall Lightning of a few years ago was developed with help from Lotus, hence its remarkable handling capabilities. I guess the Solstice and Sky are based off the Vauxhall. I'm pretty sure the Solstice and Sky share almost everything except the skin.
Comparing 914 to Saturn Sky
I believe they both have almost equal 50/50 weight distribution front and rear. They're both rear drive. They're both about the same length and height, but the Saturn is wider, heavier and much more powerful. I don't know where the center of gravity is for either. I'm sure the 914 is lower, but I just don't know how much lower.
914 2.0LLength: 159.4
Wheelbase: 96.5
Width: 65.0
Track: 52.5
Height: 48.4
Weight: 2139
HP: 90
Torque: 105
Power to Weight Ratio: 90/2139 = .042 hp/lb
Saturn SkyLength: 161.4
Wheelbase: 95.1
Width: 71.4
Track: 61
Height: 50.1
Weight: 2880
HP: 170
Torque: 162
Power to Weight Ratio: .059 hp/lb
They say the Saturn's frame is hydroformed. Is that what they did with the Elise or am I just way off? Looking at the numbers above, it looks to me like that Saturn ought to be one heck of a fun car to drive. And they say they're planning a 210+ hp redline version of the Sky in the near future.