Even though I have checked my strut tops assiduously since earlier postings this strut gave way whilst in my panel shop. It moved approx 1cm and nudged the bonnet. As we were unable to get the car on the hoist to replace the rubber bushing, the bonnet was removed fully and the the car was placed on the street. A few hours elapsed and, whammo, the strut let go. I cannot begin to tell you how horrified I felt on seeing its collapse. This could have happened on the open road with full family on board....there is a lesson here. If you have and XM or car with similar Macpherson strut and top mount, then replace them before 150000kms have elapsed regardless of how 'normal' they appear.