(1997, Mike Myers)

“In the opening sequences of the film 'Austin Powers' a location, which pretends to be London, but is very obviously the USA included in the background a Bristol Lodekka FLF in red/yellow livery, ex-Bristol Omnibus or Hants & Dorset (all slider vents)” (thanks Mark Harrington). As you can see the man somersaulting into the car is not Mike Myers!

In a later scene Burt Bacharach plays piano on the upper deck of an open-top Alexander-bodied Daimler Fleetline, formerly Trent 486 (HRC486D):

I believe HRC486D is the bus featured (in a different livery) in the TV shows Firefly, VIP and Martial Law.