Cut CO2 from driving without giving up the car?

Spotted - on a billboard in Nottingham.

Flashy advertising on eco-driving from the Department of Transport in its new Act on CO2 campaign. I've also bumped into a few of these in pop-up form on the Guardian website! While every bit of awareness and individual action matters greatly, I hope that this isn't the sum of their 'big idea' on climate change while encouraging airport expansion and wider, bigger roads.

In any case, what does smarter driving entail?
- As the billboard suggests, pumped up tyres reduce the work that the engines have to do
- Less clutter in the boot - less weight that the car has to haul around
- Driving within the speed limit ensures efficient fuel consumption
- Less stopping and starting means less CO2 - gradually slowing down and starting up again
- Keep the revs down to reduce engine wear and fuel wastage.
- Idling is wasting fuel - kill the engine while waiting for 3min+.