Plymouth Valiant Signet
Building on a worldwide record sales success in 1963, the Valiant moved into 1964 with design changes giving better economy, reliability and performance. Changes in the 1964 Valiant included a restyled front end featuring a new grille with a horizontal bars. A "Valiant" medallion was placed at the center of the grille where the bars formed a flat buldge. Vertical taillamps replaced the previous horizontal items. The ring-style rear deck decoration was replaced with a Valiant script located at the right-hand corner. There were few styling changes in the 1965 Valiants, but the 1966 Valiants had a split grille with fine-patterned insert; new front fenders; new rear fenders on the sedans; new bevelled-edge rear reck lid; heavier rear bumper; and a new roofline with large backlight.
Source: Wikipedia, 2013