The angle sensitivity of the older design was GM engineers' prescient way to combat the "Carolina Squat" trend: with a squatted rear, the reel would allow the driver to be propelled into the windshield for increased visibility and a hard lesson in consequences. In cases where trucks and vans had a lot of rake, the reel would keep them from sliding into the steering wheel while giving them a mechanical hug for being cool. The rake-protection system was originally paired with padded, crushed velvet seatbelt covers because it was assumed that drivers and/or passengers would be shirtless.
