I think they're problem was what they chose to tow a 1000kg+ van with a Kia...even a diesel one...over here we'd tow that with at least a Commodore, Falcon, Magna, or Camry V6. England has a funny way of building cars...they aren't generally large, and still people like smaller cars.
Back around 1986, when I owned a 1979 TE Cortina with a worked 4.1 liter 6 and a four speed, I had fantasies about shipping it to England to scare the hell out of other Cortina drivers...over there, a similar Cortina would have come standard with a little 1300cc Kent engine, and the higher-up versions would have had the 1600cc Kent engine. If you really sprung for a luxury version, you'd maybe be able to afford a 2 liter OHC engine. Over here, the smallest Cortina engine in that model was the 2 liter.
The larger cars were the same...a Ford Taurus or a Vauxhall Carlton was normally fitted with a 4 cylinder...maybe if you were lucky, you'd be able to get a 6 cylinder if you spent up on an upmarket version.
Probably has to do with the fuel prices...a mate of mine who spent a few years in London didn't even own a car...public transport was so good he didn't even bother. He also said that the richer people driving jaguars or Rolls Royces were not only giving the image of "look at me, not only can I afford a Jag/Rolls Royce", but also "Look at me, I can afford the petrol to feed the thing."