You might find one, but.... they are *very* rare, being handmade, and special order from Japan.
On my last car (Bluey, not Bluey II), the massive rise in MPGs (look at the gaslog for 'Bluey') was simply due to having the SuperMID, and being able to adjust my driving style. A few % was due to other mods... But when I removed them, my MPG kept rising anyway. (except the block heater - that was a major fuel saver)
My current car is auto, so the savings are not as good - however still +30% which is significant. Also I have been driving shorter + shorter journeys to save fuel (doing less miles per week etc), and yet I have kept my economy fairly constant.
__________________ Team GasMisers5 - #1 for first three rounds of the original GS Fuel Economy Challenge
Miles displaced by e-bike since 1 Jan 2008: 62.6 (0 kWh used)