Jay & all, just the saying "Like minds think alike and fools never differ", nothing more than that, no fools involved in these projects that I can see.
The rear suspension concept on SP1 and the one on my car are very very similar - hence like minds think alike!
We have intentionally added roll stiffness to replace that lost by removing the roll stiffness inherent in leaf springs and we have the suspension units slightly further out but still inside the chassis members.
Indeed with progressive spring rate and tuned monotube adjustable dampers the ride and handling is transformed.
There is always of course a concern with the mass of the rear axle in a light car going into its own modes of vibration, but there are solutions.
To those who were concerned about 'fight' in the bushes on SP1 and other such concepts, one can tune the coning rate of the bushes to build in roll stiffness. We have built in adjustable roll stiffness in another way, but no ARB of course.
Our prototype system is tuned to match the SUPLEX RS up front of course, but as Brian says the handling of the RS matches that of the std setup, but then the RS progressive spring rate and monotubes gives the ride improvement - horses for courses as always.
Cheers Peter.
