I'll try to answer some of your questions.
I ran a track event a few years with Bob Ellis, but I thought he lived in Utah.
The Mumford link did break on one S1 after many track days and who knows what .
Superformance SA, sent out a update design to reinforce the mounts . I made 2, gave one
to a fellow S1 owner and was never installed, mine has the updated bracket, but your
never going to need it.
The key to making a S1 handle well is tires, they came with a very poor choice of tires.
Easy fix with the tires.
If you are oversteering or understeering on the street with a good tire, your going to
meet your maker soon.
Read the comment about there hard to get in and out off. 6"3' and a 230 , and I get in and
out with not much of a problem.
Problems- There are no body parts to be found. And don't even think about breaking the windshield, but I have a new frame in black. Hope this helps....