Bimmers (along with some other cars) have a dot matrix around the windows. Tints don't really stick to this dot matrix very well. Some places use a "special" glue to try and make it stick better but I've never seen it come out perfect. Just something to be aware of.
2011 E92 M3 | Le Mans Blue | Carbon Leather | Eisenmann Race | Edition Grilles | pic coming soon-ish