Colin
There are lot's of simple Mods you can do to improve the mpg of the car.
However IMHO the most important thing at your early stage of ownership is to fully familiarise yourself with the normal functioning, the way the battery charge goes up and down, learn about 'Recals', 'Forced charge' and master driving in lean burn mode as much as possible.
Read as much on this site as you can as well
You can also consider
1) Radiator block, an instant 5-10mpg increase and really helps in winter.
http://www.insightcentral.net/forum/vie ... ator+block
2) Tyres pumped up to at least 45psi. +5mpg I run mine at 50psi! (Must be the Oem UK Bridgestone B391 ones thought, using any others mean a 2-5mpg loss in mpg!)
3) Use the brake light max regen trick as well to improve battery charge. +1-2mpg. Especially descending hills!
4) Maximise lean burn +5-10mpg especially on a decent journey.
5) Hot air intake +2mpg.
6) The brake and clutch switch mod +1-2mpg.
Good luck and keep us posted.
Peter UK