For those of you unfamiliar with this term, it refers to people who drive too slowly for the predominating traffic or conditions, such as motorway middle-lane travellers doing 50mph while the inside lane is moving at 60mph.
The danger of becoming a grockle in the Prius is that you spend so much time trying to be an eco-martyr by saving fuel and reducing emissions that you forget to put your foot down and keep pace with traffic on the road.
This condition is made worse by the television screen which dominates the dashboard. This features an entertaining series of arrows and flashing lights that shows you which engine, either conventional petrol or hi-tech electric, is powering the front wheels.
I still find I'm slightly distracted by the huge digital numbers close to the windscreen telling me what speed I'm doing, while the energy regeneration display is just fascinating! I have become obsessed with getting reward 'stars' on the chart that tells me the battery has recharged and I'm saving fuel.
On the less bright side are the front windscreen wipers. On one of the freezing January days when temperatures around Peterborough dropped to minus four degrees centigrade, I discovered that the windscreen wipers have a peculiar idiosyncrasy to 'skim' the surface. The heater was going full blast on the windscreen but the wipers were still having no effect at all.
Then I discovered a major disadvantage — when I called Toyota to find a suitable Prius dealer, the nearest turned out to be at Loughborough or Nottingham — an hour's drive away.