I have caused a small crack in the top plastic tab (the one which holds the front headlight in place at the top). The crack is less than 1mm thick. I can still screw in the tab fairly tightly though without causing it to crack further open and so that it holds the headlight in place quite securely. I was replacing both front headlights (as both were damaged from a small front end bump) and front bumper in preparation to get it through an MOT. I was wondering whether this small crack will be an MOT failure as I had just bought these headlights and I was fitting them onto the Micra so that it passes the MOT.