Hobs with water reservoir

Are these the ones where there's a continuous flow of water under the burners that carries away all the gunge? I've wanted one of those ever since I saw one on the TV, but I've never seen them anywhere else.

My mates got one, Smeg brand I think, cost about £2.5k of internet about £3k from a shop. Dominates his kitchen wall.and it does stay clean as all the boiled over rubbish and cooking juices from the griddle thing fall into the water. Has a filter/collection box thing that needs emptying as it doesn't put the crap down the drain. Has had numerous problems with cooker elements overheating and blowing, a pain to replace as it has to be unsiliconed and unplumbed to get access to wiring.

Making your own must be diyable ;)

NT