Talking about cars tankering isn't a realistic comparison. My 1500kg car only carries about 50kg of fuel, 3% of its empty weight and the effect of weight on fuel consumption isn't nearly as great as for a 'plane. Not much saving by running it half full. Are there any airliners where that proportion is less than 30%? The BBC article talks about tankering three tonnes - it doesn't say what aircraft, but isn't that about 7.5% of the empty weight of a 737?
Also the impacts from oceanic tankers are only about 1% (per tonne km) of those of an airliner. Rail is about 2.5%. Road maybe 20%. Tankering can't be justified on the basis that the fuel had to get there anyway.
I'm certainly not a hater of the industry, but I think a carbon tax on jet fuel would be the easiest way to help the bean counters make the right decisions.