A few weeks ago the user 7808mg was selling off the air intakes from a Vectra describing them as sold by a company for the Astra. Two sellers are now doing it again using exactly the same pictures. Are people really stupid enough to pay over the top prices?
If you want the air intake and the small adapter to fit to the airbox you can buy them from any Vauxhall main dealer for £13 inc VAT. It will make NO difference to performance when fitted to the Astra. I hate seeing people ripped off.