A fellow by the name of Jay Wright was involved in a fairly simple accident that turn violent and almost fatal several years ago at the Runoffs. The seat mounting of his showroom stock car broke when it flipped.[/b]
Be careful of jumping to conclusions.

"Back in the day" Showroom Stock car HAD to run FACTORY SEATS. That's right: no race seats (or race pads, or even weld-in cages) allowed. The problem with Jay's seat in 1993 was NOT that it pulled out of the sliders - it didn't - but the factory seatback adjustment mechanism broke and the seatback was no longer supporting him. Coupled to a poor rollcage design (the main diagonal it collapsed), it was nearly fatal to my friend.

Jay's accident was the impetus for requiring race seats and better weld-in cages for Showroom Stock cars.

To the question at hand: there is no restriction against using stock sliders, nor is there a requirement to have statically-mounted seats (i.e., you can have adjustable seats). SCCA is surprisingly mum on the issue, requiring only "secured" seats (I don't have the exact verbiage handy.) I have personally recommended - and mounted - racing seats on stock sliders in many cars, mostly Spec Miatas, and I'm comfortable with the installation.

However, as I Tech inspector, I am additionally suspicious when I inspect a car with one, to verify its security.

Greg