You offer a Manual in 3 of the 6 cars/hatchbacks you offer, please make that number 4 and put a manual in the Malibu!
The 2.0T the Malibu uses is the same platform and engine as the Buick Regal GS FWD, which offers a manual transmission. So obviously the Malibu could technically be had with 3 pedals.
I know it wouldn't sell worth a damn, but there'd be so minimal R&D cost associated with it, it wouldn't kill you financially to offer it.
Ford offers 3 pedals on the 1.6T Fusion, so why not one-up them with a 6-speed 2.0T Malibu? Spice up the offerings a little bit Chevy!
I will commend you for offering one on most trim levels of the Cruze, Sonic, and Spark though.