I would be very careful. A wheel with a ET45 and 8" wide will be 12mm further out, plus the extra tyre width will take it to at least 17mm. This may even be Greater depending on your tyre choice. Even on a standard OEM set up IMO you'll get rubbing, More so when you press on a bit going around corners with the tyre wall flex.
I was told by TYREMEN of Hull that they were not prepared to sell me ET45 / 8" wheels because of this.
Martininwillerby