I know how it feels to have something hitting the windscreen like that. We were driving up the M11 behind a lorry loaded with wood, when all of a sudden a big bit of wood about 2′ long and 5 or 6 inches wide come flying off the back, twisting through the air. We could see it coming right at us, and sped up hoping we’d get underneath it. Didn’t work, and it hit the windscreen smashing it to peices. Had to spend a good hour in the hard shoulder recovering from the shock.