A GLX model was placed between GL and SE level and was advertised as a "sports pack". A limited run of 1,016 "Peter Wherrett" editions of the GLX were built (option A05), named after Australian motoring journalist Peter Wherrett who was given the task of improving the handling of the Sigma by MMAL after complaining about it. The improvements included 15-inch Globe "Montego" alloy wheels fitted with Pirelli P6 tyres, Recaro seats, Momo steering wheel, Sonic extractors, as well as lowered coil springs and Bilstein shock absorbers.