That piece is not a side intrusion element. It is simply a way to connect the pedal box (& passenger) back to the chassis.Spyder's web site is still up. At the very least, I want to get a roll bar and side intrusion beams fairly soon - I hate just having lap belts and I'm not comfortable mounting harnesses to the back wall of the interior. Of course, in a serious accident, you're probably a goner no matter what, but everything helps!
The arrangement is supposed to protect our lower legs in the event of an offset (or full?) front crash, by keeping wheel & tire from encroaching.
Yes, I've grown attached to my feet....
For that longitudinal member (hidden in rocker panel) to give us intrusion protection, we'd need to be on a go-kart track....