On the Cupra Allards fitted a sandwich plate with oil temp and pressure gauge censor fitted to it. On my 2.0BKD PD140 engine in the Audi there is a plug on the side of the engine that was removed and a doubler fitted to fit two censors, oil pressure and temp again. There might be a plug on the 1.9 engine but i was meant to of had an oil cooler fitted but never got around to it before i rolled the car. I have been told that you get a more accurate reading by fitting the censor in the sump not a sandwich plate by several people but weather there is any truth or much difference in the temp to make any difference i don`t know.