Go Let It Out

Filmed in Surrey, England, using a silver-painted former London Transport AEC Regent III RT1591 (KLB713). This bus was later deroofed in The Mummy Returns.
There are actually four buses seen right at the beginning: the RT, a DMS-class Daimler Fleetline, a Plaxton Elite III coach and a second dark blue doubledecker, which appears to be ex West Midlands PTE. Nigel Newman cofirms the blue/red/white DMS to be MLH455L, ex London Transport DMS1455, in the livery of Associated Bus Ministries: