So, we still couldn't rent a car in Trikíla, but we did catch an inter-city bus to Kastráki, just below the monasteries of Metéora. On arrival, we discovered that there was no bus available at this time of year and, since we didn't have a car, we had to go for the hiking trail as described in my guide book which turned out to be a wonderful way to reach the monasteries!
(Click on any thumbnail image below to view a medium-sized enlargement.)