That is true but there is more to the story. Jim Hall originally design the Chaparral 2H to use a fully enclosed cockpit featuring a series of mirrors so he could see out. It only had a single front windscreen and a window either side. There were blind spots where the front wheels were.
The car was originally intended to race in 1968, at which time Hall himself was still driving before he had his nasty shunt at Las Vegas. But delays in its completion meant it wasn't ready until the 1969 season, by which time John Surtees was recruited to drive it. But Surtees hated the car, didn't like the enclosed cockpit, and demanded the drivers seat be raised, and an opening cut in the roof so he could see out over the top. According to Jim Hall, this completely ruined the cars centre of gravity.
But in creating the changes meant the 2H wasn't ready for the start of the 1969 Can-Am, so a customer McLaren M12 was purchased. Initially it ran as supplied, without the big rear wing. The wing appeared for the first time in Round 3 at Watkins Glen.
The Chaparral 2H finally made its race debut at Round 5, at Edmonton, but Surtees was way off the pace, qualifying over 5 seconds behind pole man Denny Hulme, and the situation never really got any better. In fact, Surtees returned to the McLaren for Round 7 at Bridgehampton where he immediately qualified third fastest and was much more competitive. The 2H returned for Round 9 at Laguna Seca with a MASSIVE wing perched up above the car (as below), and raced only once more, at Riverside. This was one of the few Jim Hall designs that didn't work, but it would have been fascinating to see how it might have performed without the changes.