Myself and Kitch (Who I think is a forum member) are about to build two MX5 based roadsters based on the Saturn plans but with a few tweaks.
In the pictures you can see my design for the back end of the chassis which I believe will be far more solid than the original. This is to scale and uses the same pick up points as the saturn design.
http://www.flickr.com/photos/66567276@N05/6708878431/
http://www.flickr.com/photos/66567276@N05/6708878127/
http://www.flickr.com/photos/66567276@N05/6708878613/
My car will be powered by a very low mileage 1.8 VVT engine producing 153bhp and my intention is to build a car weighing no more than 550kg, I'd initially wanted 500kg but the more I look into it the less likely it looks.
We plan to make the 1st cut's this weekend so I'll keep you updated with any progress.
Paul