Vauxhall Zafira and Meriva
2009 ad for Vauxhall's MPV range gave my children an excuse to namecheck the Australian children's TV show about teenage mermaids, 'H20: Just Add Water'. For here we see actress Phoebe Tonkin (Cleo in the show) sitting on a bus minus tail and pulling the seat across the gangway closer so she can talk to an unsuspecting young man. (thanks to William and Sarah Annells for identifying the actress. No id for the bus, sadly, but I'd guess from the context and the young man's haircut that it's Australian)
A 2003 advert features a red cartoon double decker bus.
A January 2009 ad celebrating 25 years of Virgin Atlantic and set (obviously) in 1984 features NPJ472R, a 1977 Leyland National new to Alder Valley in its National Bus Company incarnation. Although the bus is of an appropiate age, and it carries the Alder Valley fleetname, the green/yellow livery is that of Alder Valley South, which was not formed until 1987:
A man apparently talking to himself on the upper deck of a London Transport AEC Routemaster is actually using his Virgin cell'phone.
Features an unidentified London Metrobus.
A 2007 ad in Vodafone's 'Make the most of now' campaign features Arriva Dennis Darts with Plaxton Pointer bodies (screencaps by stronghold):
Shot partly in Great Yarmouth, one advert features a Duple Dominant coach of Belle Coaches.
A 2011 advert features the rear of white Dennis Dart/Alexander KP54BYR, but I'm not sure about the engine sound - more like an RTS?