Go for the rear tints. You need to ensure that if smoking the front windows they are still 70% clear. As these are already tinted you are likely to go over. Dont touch the windscreen obviously. Also you must inform the insurance as they will not pay out if you need them to. My insurance company wanted around £70 a year more, so I fitted a blind in the back instead. I dont know about putting black on black. It looks ok where I have seen it done on older versions in other colours. You might want to find a few pictures on the net to see if it looks ok first. Personally I like the chrome on the M Sport.