Wow... Errm my Uncle's step-brother works for Hyundai and he get's pissed off about it all the time...
That's because Brits are weird.
Another thing, what's the deal with "aluminium"? Even its discoverer decided to call it aluminum (after switching from alumium, originally). Apparently it was some douchebag literary twat that decided he like "aluminium" better because it had a more "classical" sound.
From the WikiPedia article: Davy settled on aluminum by the time he published his 1812 book Chemical Philosophy: "This substance appears to contain a peculiar metal, but as yet Aluminum has not been obtained in a perfectly free state, though alloys of it with other metalline substances have been procured sufficiently distinct to indicate the probable nature of alumina." But the same year, an anonymous contributor to the Quarterly Review, a British political-literary journal, in a review of Davy's book, objected to aluminum and proposed the name aluminium, "for so we shall take the liberty of writing the word, in preference to aluminum, which has a less classical sound."