Acer and Grem were two secondary villains in Pixar's 2011 film, Cars 2. They are the rejected and forgotten lemon cars, who worked for Miles and Professor Z to reject back to the car world.
Acer Pacer was been a outcast to the car world, while Grem Gremlin was mocked for his design throughout their years. Until somewhere in 2011 where they joined on the group "Lemons" to revenge and reject back to the world, so the modern cars will be mocked like they were once before. As the members of the Lemons, the two become partners, working for Professor Z and Miles Axlerod.
Acer was a beat-up green colored AMC Pacer, while Grem was a rusty, and dented AMC Gremlin.