At present, auto renewals do not create a new invoice but adjust the original subscription invoice (or the first one where auto renewal was setup).
It is standard accounting practice in the UK and (I believe) the EU to have a unique invoice for each 'sale'. Indeed, the UK's tax agency, HMRC, specifies this.
As we grow and get more auto renewals, we get increasing queries as to where members invoices are. The only way around this is to manually create invoices, which is impractical.
I have mentioned this in the general forums before, but it is a growing issue so thought I would make the request more formal.