Bob drives a blue HB Deluxe 2 door in the first episodes , then he and Thelma use an HB Deluxe 90, cannot remember the colour, light? however pedantically I do recall it was a four door( Saw the episode with the Viva outside the tower block but I thought it was a Pampas Green SL( age related memory maybe dodgy) however in the film a red 3 door Chevette seen parked next to the "grey" 2 door SL, and is used to tow a rather large looking caravan on a Holiday which is supposed to be in Northumberland but is clearly on the road from Hertford to Hatfield,presumes filmed near a Herts film studio, OK I'll remove my anorak now .