GMPartsGiant.com offers the wholesale prices for genuine 2019 Cadillac ATS Coupe parts. Parts like Fuel Tank & Vapor Canister are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 4 Cyl 2.0L, 6 Cyl 3.6L. Model Code: 2 DOOR COUPE, 2 DOOR LUXURY COUPE, 2 DOOR PERFORMANCE COUPE, 3 DOOR PREMIUM COUPE.