The rear struts?
I know when I installed O/B struts on my leg, the rears rubbed up against the metal shrouding, I thought oh ************!
However, once you lower it off the jack, the struts will pull out from the metal shrouding, so not to worry - Install them, lower and they will make some noise but then they will never make another noise, even if you jack the car up to swap tyres down the track.