This side view from down low gives a good idea of how much the fabric stretches when installed. If it wasn't for the stretching, those lines would all be straight from one bow to the next. If you compare the slight inward curvature of the fabric between the bows to a straight line between them, you realize that it's not really a lot of stretching there. These compound curvature shapes allow the fabric to be in tension almost all over, resulting in this fabric shell being quite stiff in a turbulent environment, so it probably won't flap and rattle nearly as much as you may imagine.