Having seen a a brand new white XF with rear windows tinted using the 20% option, I have had mine done which is dark azure blue. I hope it will, as well as looking good, reduce in-car temperatures when parked in sunshine. Living in Somerset I was recommended White Horse Tints in Westbury, Wilts BA13 4QT they did the white XF and they did another great job on mine and I would recommend them. A bit of advice, there is no need to go darker than 20% as this works well!!