I have had really good luck with Tint King in Billerica. Over the past six years they have tinted over 5 different cars for me. With my e92 I was concerned about the dot matrix on the top of the back window.They ended up applying a clear black film on top of the matrix, then tinting over it. The result was an absolutely flawless tint. I highly recommend them.
http://www.tint-king.com/