Gabby says she drove a stick shift once in high school. However in season 7 episode 8 she drove Hector's truck which was a stick shift and she she drove it better than this car.
When attempting to move the car Gabby has trouble because it has a manual transmission. Later when in the same car Gabby gets sick and has the driver pull over. When he comes to a stop you can distinctly see the reverse lights come on momentarily. This only happens on an automatic transmission when shifting from drive into park (moving through reverse).