Cadillac ATS (2014) is 219 mm (8.62 inch) longer and 2 mm (0.08 inch) wider than Mercedes GLA-Class (2016).
Mercedes GLA-Class (2016) is 74 mm (2.91 inch) higher, 109 kg (240 lbs) lighter and has 40 liters (1.41 ft3) bigger cargo space than Cadillac ATS (2014).