Radical
lightweight
Turbodiesel
(Turbo) Lag
Gauges
Subaru
Undercarriage.
Electric supercharger (AKA intake-installed electric power limiter)
Rally wheels
Sat nav.
Valvetrain
Nitrous Oxide
Electronic Handbrake
Eibach Springs
Sparco
Journal Bearing
King Pin
TurboCharger
Running Boards.