how about two settings for spring stiffness, one for the "soft" end (first part of the travel) and one for the "hard" end (last bit of travel), with intermediate values calculated along a curve between the two?

it would allow us to lower the cars a bit, and get a better center of gravity, without sacrificing small bump compliance too much, and would probably be easier for people to get their heads around than 4-way dampers (which i also want...).

Quote from evilgeek :

how about two settings for spring stiffness, one for the "soft" end (first part of the travel) and one for the "hard" end (last bit of travel), with intermediate values calculated along a curve between the two?

it would allow us to lower the cars a bit, and get a better center of gravity, without sacrificing small bump compliance too much, and would probably be easier for people to get their heads around than 4-way dampers (which i also want...).

I've suggested both things you've mentioned some time before too and frankly, if rallycross has any chance of taking off we will need them both. The really big benefits of these 2 components are the ability to combine excellent response and handling with very good wheel travel and bump compliance. Imagine RB4s with progressive springs and way dampers. Or even better, RB4 rally edition with these 2 components and maximum travel increased to 250mm. There might be hope for rallycross yet.