4. Tuner Category - Anti-Roll (Sway) Bars

You can add any sway bar, including fancy splined ones that don't directly replace the OE sway bars.

Tuner Category Anti-Roll (Sway) Bars - Full Rules

Substitution or removal of sway bars (at one or both ends of the car) and supporting hardware (brackets, end links, bushings, etc.) is permitted. Tow hooks may be removed for the installation of sway bars.