Convex or faraway mirrors are not a legal requirement but if your mirror has an indicator fitted you must replace it with one that has it too.................insurance companies wouldn't have a clue as to what mirror you had fitted anyway, having had a couple replaced due to sideswipes, I could only show the assesor the mess left behind but it would be advisable to let them know you have a Clearview or similar fitted so they will replace it with the same or they may go the original, no actually the Clearview would be cheaper than OME mirror so they would be happy.