Paul,
Fitted new camshaft on 2003.Touran some time back,from memory,I think it was beside the front bearing cap I found a small alloy plug sitting on cylinder head when I removed cambox which seemed to have been pluging an oil gallery.There was no oil light complaints from customer,just noise from worn camshaft,could be losing oil pressure from this area,Maybe worth checking,Regards,Christy Doyle