It was that simple! I cant believe I could have missed it for so long and spent so much money on trying to chase down one nasty noise! Why did the dealer never find it when under warranty? I've bought and fitted almost every part on the front end and as I replaced each part the noise got worse. OK I'll stop teasing. For my particular vehicle it was as simple as below. Yours maybe different? Who knows. The torque for the top strut mount nuts should be set at 27nm They were barely set at 19nm Did them all at 27nm and I've had not one clunk since! Now done a few hundred miles over country lanes, with big potholes, with just normal suspension noise for the type of road and tyres fitted. Its like Christmas has come early