Ours has been knocking occasionally on the N/S/F, not all the time and our cooling fan will stay on for 5 - 10 mins after parking up and switching of, again its not all the time and very random. Another thing it has started doing is sounding very harsh and ratley from under the bonnet almost like an exhaust heatsheild vibrating or something, and another thing thats just started is the 'Run flat' tyre warning indicator in the centre of the rev counter has started coming on and we have not even got run flat tyres on ours!! I have reset it twice the correct way and checked the tyre pressures, and its not like i dont know anything about cars as i have spent the last 15 years in the motortrade and the last 5 years Mot testing!! Think i will stick to my classic cars, less to go wrong!!!!