We put our findings to the EU's Competition Commission, who said its purpose is to ensure motorists are free to take advantage of prices across Europe, not to harmonise them.
We tried the UK Competition Commission, who said it was a matter for the Office of Fair Trading in the first instance. The OFT, however, said: 'We cannot speculate on any actions without receiving a complaint and checking this against our prioritisation framework.
'If any consumer thinks that they are being unfairly disadvantaged, they can make a complaint to the OFT which will consider carefully whether to launch an investigation.'
We're not allowed to register a complaint with the OFT on your behalf. So if you're one of the 13,774 who have bought a Focus this year, or one of the 126,928 who bought one in 2007, perhaps you'd like to drop the OFT a line at Enquiries Unit, Office of Fair Trading, Fleetbank House, 2-6 Salisbury Square, London EC4Y 8JX.