Right...I have just spoken to the horse's mouth...my local National in Aberdeen.
The price includes labour, oil and filter...and you can also take the 10% off voucher with you...all in cost of £27.54.
However, there may be a minimal charge (£5-ish) if an undertray needs to be removed.
However, no promise or knowledge of how long this price will last.
Do you think a main dealer would price match...haha!!!
Regards,
Billy