Progressive rear springs for Prius?

[nfschlaack]

Hey all,

I have seen other threads for rear suspension solutions/upgrades but didn't find anything about these kind of springs. I am wondering if there are any after market progressive coil springs that are made for the Prius. I know they exist or used to. I had them put on a 1985 Buick Regal years back and worked pretty well. They are/were like two coil springs in one. One section pre compressed and the other in normal configuration. They worked well when loaded lightly and "kicked in" when heavier loads were applied. It was simple technology and would work very well in this application in my opinion.

So the obvious question is, does anyone know of such a product and/or where I could get more info?

Thanks.