[Parax]

I use the Torque app, here's a demo of the torque video overlay:
http://www.youtube.com/watch?v=B7v79M861yk
The dashboard display is very customisable, and has many screens available, Its ideal for a cradle mounted screen.
There is a free trial version but you can't load custom pids.

Torque is Generic (it'll probably do the leaf too with the right Pid's) You'll need a list of custom PiDs for the Volt/Ampera there's a good one here:
https://docs.google.com/spreadsheet/ccc?key=0AvK9F6VeA7dvdFUwSjBzR2FQM1BJTWZoLW43ZFdoTFE#gid=0
You can load this file into torque directly.

There is also a list for OVMS here:
https://github.com/markwj/Open-Vehicle-Monitoring-System/tree/master/vehicle/Car Module/VoltAmpera

 

[Parax]

http://www.evchat.co.uk/viewtopic.php?f=14&t=554

 

[Parax]

See tab 2 on the google spreadsheet for instructions on how to import the whole file.. (it'll save you tapping them in..)

 

[Parax]

SOC U is useable (between 21.5% and 65%) expressed as 0-100%
SOC R is real as a total 0% to 100% expressed as 0-100%

21.5%R shows 0%U
65%R shows 100%U

*Edit those figures are not right, I picked them from the sum on the spreadsheet. but I havent back calculated the actuals.. you get the idea..