I booked a car from a company called Green Motion many months ago. We were expecting someone from Green Motion to meet us at the shed that is Terminal 3, or at least to answer our call to its office nearby. Plan B was hastily formed and put into effect. This involved taking a courtesy bus to the Avis depot (which seemed to be closer to Bristol than Terminal 3) to become a "walk-up". Apparently a walkup has criminal tendencies that justify some additional charges, but at least the staff were helpful and had a car available.
We drove to Kent.
We arrived at Old Wives Lees at bout 11pm, just as our hosts were taking their phone off the hook. Plan C? No other accommodation was available so we slept in the car. Early next morning we made belated contact with our host who cheerfully suggested that perhaps we should have contacted him earlier.
After finally getting some sleep we set about exploring this fascinating area, starting with Canterbury.