InfinitiPartsDeal.com offers the wholesale prices for genuine 2015 Infiniti Q40 parts. Parts like Rear Axle are shipped directly from authorized Infiniti dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 6 Cyl 2.5L, 6 Cyl 3.5L, 6 Cyl 3.7L. Grade/Trim: Journey, Leather, Premium, Sport, Sport Premium.