I heard this on the radio this morning. I had already booked my service for next week a week or so back. I phoned the dealer and asked if they are honouring the 20% off for works already booked to happen during the promotional period and he said they would so that's a bonus for me and was worth the confirmation by the dealer themselves. (I expect they know people will just cancel and rebook).
Saves £120 for the round of servicing I have coming up
