I am driving a hire car, a new (about 1,000 miles) UK Ford Focus with diesel VETEC engine. This evening I noticed a yellow warning light in the speedometer that I don't recall seeing before (I've had the car about 4 days). It's a sort of snowflake shape and comes up red during the self-test when the key is first turned on. Trouble is, it has been on steady (yellow) for the last several miles and I have no clue what it means. It's a hire car so of course there's no owner's manual anywhere in it. Off the top of your head, have you any idea what the light might mean? I certainly don't want to damage the car by driving it if it's low on oil or something of that nature.