my head unit has 4 screws one in each corner, 3 of them go in tight and have a white coloured bit they screw into.
1 of them just goes straight through does not grip or screw in jus goes all the way in.
Any ideas of what the missing bit is, how to get it or refit it
picture shows what I mean it is not my own car here it shows a little white bit inside each hole. mines is the same but one is not there?
I've tried longer screws and thicker ones makes no differnce, can get my hand behind but cant feel anything that has droped off or come away.