FordPartsGiant.com offers the wholesale prices for genuine 2018 Ford Flex parts. Parts like Rear Window Wiper and Washer are shipped directly from authorized Ford dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 6 Cyl 3.5L Cyclone Petrol TIVCT, 6 Cyl 3.5L DOHC T/C. Transmission: 6-Speed Automatic Transmission 6F50, 6-Speed Automatic Transmission 6F55.