4-seat "verts" should not be track cars.
They can be used on the track casually, but they should definitely not be dedicated track cars. S2k's, Miatas, and others which are dedicated convertibles tend to be much more natural track cars than 4200-pound M3 'verts. The excess weight causes them suffer in acceleration, braking, and cornering.
M3 Sedan LCI - AW/Black - 6MT - no moonroof - no folding seats - RAC RG63 - clear bra by Omega Werks