Some cars leave a paper trail; the McLaren M16 left a name and a place in Mclaren's list. What follows is what can be said with a source behind it. Its designer of record is Gordon Coppuck / John Barnard.
The story
The McLaren M16 was a race car designed and built by McLaren between 1971 and 1976 for American open wheel racing. It is the most successful car of the 1970s at the Indianapolis 500 with three wins in 1972, 1974 and 1976 and the last one to win with the Offenhauser engine.
Its place in the line
Where it sits in Mclaren's history is not in doubt: the McLaren M15 came before it; the McLaren M24 followed it. Nearby in the Mclaren catalogue sit the McLaren M15 and the McLaren MCL33.