"Also when is the diesel version coming out? that [sic] would be more efficient that [sic again] the petrol one I would have thought."
Most (all?) hybrid cars use a modified Atkinson cycle, not an Otto cycle, increasing the average energy efficiency of and reducing pollution produced per energy extracted by the engine. I believe this reduces the gap in desirability between diesel and gasoline engines (except for volumetric energy density and per-joule retail pricing in the respective fuels).
"I still can't get my head round the 'electric' car arguement [sic]. If you have to burn 'stuff' (coal, oil etc) to create electricity to fill up the cars where is the saving?"
Chevrolet figures they can get this car to drive around four miles per kilowatt-hour of input electricity. If charged only at night, that works out to one cent per mile at present residential electricity rates, and the power is typically produced by power plants that are optimized for producing power with minimal pollution. Whereas burning gasoline in an engine in a car typically gets fifteen to sixty miles (depending on the car) per gallon (currently $2.40 to $3.00) working out as four to twenty cents per mile, and that being run through a power plant optimized for constantly moving itself around and being able to rapidly switch off and on. Furthermore, technically the electricity could come from some "nice" source like non-toxic solar cells made out of seaweed and bubblegum, as soon as that's invented. (Meanwhile we'll use nuclear-waste-generating, bird-chopping, fish-grinding, rainforest-clearcutting, people-starving transition technology, in addition to the classic "find it and burn it" power generation.)
"Those are nice figures considering they forgot to meantion [sic] how much energy it takes to create one (so carbon produced), and the metal and processes needed to create the battery."
EPA mileage figures have never included any reference to the energy, raw material, pollutants, etc. involved in creating a vehicle. So there's nothing odd about this EPA mileage figure not including that for the Volt.
"Great - A car that is only economical on the kind of journeys where you should be walking and biking anyway."
Perfectly true. Except that now you don't need one of those specialized bikes that holds the wife, two kids, six sacks of groceries, and which keeps the rain off and gets you where you're going at a mile a minute on the freeway.
"I'd love to see the repair bill when fixing that thing after its warranty lapses. Also, I'm guessing resale values of used ones will be crap as is always the case for vehicles like this. That's going to suck in a few years when people start trying to trade them in."
All first-generation vehicles suffer these sorts of problems. I suppose that's why we should never innovate.
"Considering the Prius when driven NORMALLY was less effecient [sic] than a Golf diesel, ..."
Efficiency has many meanings. The Prius never shits a diesel stench-cloud into the air I'm trying to breathe, and so in terms of "volume of carcinogenic crap that enters my lungs" efficiency, the Prius is a wonder. (Not just from burning gasoline - also from using the modified Atkinson cycle and spinning constantly at the speed it thinks gets the most energy and least pollutants out of the fuel.)
"If they would just shorten the test loop distance so that the petrol engine isn't actually required during the so-called test, then it would achieve INFINITY miles per US gallon."
_I_ think they should give the car's mileage as an algebraic equation. Then everyone would be perfectly capable of comparing this car's "actual" mileage to other vehicles by simply graphing the various equations along with a curve describing their typical daily driving distances by frequency. That would also allow them to do some calculus to determine their actual fuel savings between different options. Nothing could be easier*! (* Not while still being this correct.)
Paris, because I'd like to do a couple integrals with her.