 For 1963, the Grand Prix received the same styling changes as other full-sized Pontiacs such as vertical headlights and crisper body lines, but also received its own squared-off roof line with a concave rear window, along with less chrome.This concave rear window was duplicated on all Tempest/LeMans four-door intermediates in 1964-1965.For 1964, the Tempest and LeMans' transaxle design was dropped and the cars were redesigned under GM's new A-body platform - frame cars with a conventional front-engined, rear-wheel drive layout.