It's just a building yard so it doesn't matter if it isn't lovely to look at to be fair. I did think about one but it's a pain in the ass getting them delivered.
2015 E Class coupe 220 diesel bluetec, 2009 Mitsubishi Colt 1.3
I was going to say a poly-tunnel but I've been beaten to it. The other alternative is to buy a used prefabricated structure which often means dismantling it your self to get a real bargain.
Mine came with 4 stakes that you screw in to the ground and then fix the bottom of the 4 legs with steel cable to them. As additional fixing I bought some heavy duty tent pegs and fixed the legs down both sides. I had a friend with a heavy duty sewing machine cut and fit some zips on the far end to make a smaller door so that i didn't have to open the main one unless i wanted to get the car out.