It's pronounced 'seed' in case you're wondering. Unlike many invented car names, we think it's rather appropriate.
Source: Kia Motors UK
They're talking about the Kia cee'd. Apparently the "ed" part stands for "European design" and was its codename during the design stages. The letters "ce" were added to represent the European Union (formerly the European Community, or "community of Europe". Sounds a bit mangled to me - or perhaps that's frangled...?)