When it comes to range-extender / top-up systems for electric vehicles, I wonder why there isn't a move to compact gas-turbine generators, like in the concept Jaguar from a couple of years back?

For the sake of clarity, the gas turbine would only be driving a generator as a pure range-extender / battery charger, it would not be connected mechanically to the drivetrain.

They're much easier to package than a conventional petrol / diesel engine, run at high rpm so turning generators rapidly for high output, don't need cooling systems, can run on any fuel that burns, etc.

out that if push came to shove you could run your diesel car on a veggie oil blend-you sure as hell can't do that with a petrol motor.

Bio derived ethyl or methyl alcohol? You don't need significant modifications to operate a petrol engine on E85. Methanol is a different kettle of fish

Bio fuels are (rightly) faling out of favour because of concerns with competition with food production.

Why do you say that it is a nail in the diesel coffin? The Kers recovery system can be used with petrol, diesel or any propulsion system-it's merely a kinetic energy recovery, storage and delivery system.

Diesel propulsion is the fuel of the future - you can grow the fuel in the field next door to your house, if necessary you could use the raw oil produced from the crop to power your diesel vehicle. I would add here that I am not a brew-your-own-diesel-from-used-chip-oil enthusiast, but merely pointing out that if push came to shove you could run your diesel car on a veggie oil blend-you sure as hell can't do that with a petrol motor.

I don't think any fuel that require valuable arable farmland is one to invest in - arable farmland is needed for crops for food not fuel for cars.

I still think the fuel of the future is electricity powering cars with the range of petrol/diesel cars if not more.