AMT 948H - Margaret Thatcher's P5 when she was Health Minster. 58 ROV - the P5 was launched in 1958. 73 ROV - t he P5 ceased production in 1973. JGY 280 - The Queen's first P5 in 1961. JUU 570 - Harold Wilson's first P5 when he was PM (it had previously been on his Humber Super Snipe and his Imperial).