Found it:
Myth about Racing Harnesses:
They are safer than seatbelts.
The Truth about the myth:
True and False.
Details:
The statement is true, but only for dedicated and properly set up race cars, NOT street cars
A Impoperly installed Harness (IE, one without a proper cage and/or harness bar) can cause severe spine injuries, even in the case of mild impacts.
Should you be dead set on installing one:
Shoulder harnesses should be attatched no lower than six (6) inches below the shoulder line and at an angle nomore than fourty-five 45 degrees from the top of the shoulder to the mounting point. I deally the seat belt should be mounted evenly with the top of the shoulder. Leave some length of harness webbing between the driver and mounting point for adjustability.