MoparPartsGiant.com offers the wholesale prices for genuine 2005 Dodge Magnum parts. Parts like Horns are shipped directly from authorized Mopar dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 6 Cyl 2.7L, 6 Cyl 3.5L, 8 Cyl 5.7L. Transmission: 4-Speed Automatic Transmission, 5-Speed Automatic Transmission.