After a fair bit of research, I decided the ideal spec was 12 bars, low miles (30,000-40,000), no indication of motorway thrashing, little or no rapid charging and as late a year as possible.
A larger (30kWh) battery became available later in 2015 but, on looking around, these cars were scarce and had fewer bars than the best 24kWh cars, possibly suggesting people bought them with an eye on longer distances, probably using rapid charging.
This was only a theory, but I decided to stick to my guns on the range I needed and settled for the 24kWh car with the best possible battery condition.
Which one to buy?
There are three versions of the ZE0-generation Leaf, called Visia, Acenta and Tekna.
Rationally, the best choice is the Acenta, because although it lacks creature comforts like a heated steering wheel and heated seats, it’s cheaper to buy and the tyres for its smaller wheels are less expensive.
The Tekna does have the heated things, which I wanted for Scottish winters, and although the larger alloys take more expensive tyres, they also look nicer.
I’ve had my fill of traipsing around the country looking at used cars (which these days can cost more than it saves), so I was grateful to spot a likely candidate at a local Nissan dealer. It was a fair bit more expensive than I had been looking for, at £7995, but was a 2015 Tekna with just under 30,000 miles on the clock, 12 bars of battery health and a 12-month dealer warranty.