Recently noticed some black oil drips on the driveway. Looking under the car next to the oil sump there is a round plastic casing which seems to be wet with oil after longer journeys. any ideas ?

Bought our 68 plate n connecta 18000 miles in September 2020 and have recently had the amber engine malfunction light come on. Its still under warranty at Lookers, so they plugged it in and swapped a temperature sensor which they said was the reason for the light. That fault seemed to clear but now ...