Ever wonder why NASCAR racers run at over 200 mph, but do not use air bags? One of the reasons is their highly effective seat belts. Racing harnesses are designed to hold the driver much more firmly into the seat than a normal street seat belt. Not only will a properly designed and installed harness keep the driver safe on the race track, harnesses can also help the driver stay put during hard cornering. The downside is that these harnesses do not extend like normal seat belts. Once you adjust this, it stays rigidly in place, keeping you from leaning forward at all. A correctly adjusted race harness should be tight enough that it may take a bit of force to get it buckled.