We bought
CG Locks for our
track day yesterday. If you don't have a racing harness/seat these do a really good job of keeping you solid in your seat. No more bracing yourself to keep from sliding around, and you can brake hard w/o sliding at all. Just a win all the way around--and cheap relative to most mods.
Jdl1pt found them for 37 bucks or so on
Amazon.