Spoke to a contact in Vauxhall today.
The Astra Coupe goes out of production in September/October with sales officially ending at the end of 2004!!!!!!!!!
I called him to get the 18" alloy wheel info and was told, info is hard to get now as it is a 'dead model' as far as Vauxhall are concerned.
It is making way for the new Astra H 3dr!!!!