Not to blast Korey, but our experience has been Mazda6 in low to mid traction. Once Traction is above medium we switch to Speed6. We have found that the Speed6 in high traction will calm the car down. Obviously, your results may/will vary.
Regardless, a Mazda6 or a Speed6 is a good starting place for rubber tires on carpet.
Team XRay, RCAmerica, Motiv, Gravity RC, Schacht Design Works.
Drive it, Dont slide it!