Go to Halfords buy a £15 one, put it on the car in the garage gets some pins and pin fit it, then mark with tailors chalk to trim allowing extra for seam edges. Now press gain
onto the sewing machine to stitch up the seams and make good the edges. pop down the local sewing shop and buy some strong elastic and stitch on hoops to hold down in place and then proof with tent proofer. Job done. and it will cost about 20% what you looking at. Mine work a treat and is TOTALLY water proof, folds up flat and goes behind seat.
