FordPartsGiant.com offers the wholesale prices for genuine 2007 Mercury Grand Marquis parts. Parts like Heat Shields- Exhaust System are shipped directly from authorized Ford dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 8 Cyl 4.6L Romeo SOHC EFI. Transmission: 4-Speed Automatic Transmission 4R75E Livonia.