You should have got a 'BMW New Bike Warranty' booklet that came with the bike originally. There is a form in the back to complete & send off to get the warranty transfrerred into your name. That way any correspondence such as recall letters will go to you rather than the previous keeper. If you didn't get the booklet, I understand that you can get your dealer to change the address for you.
..you could also ask what work the previous owner had done under warranty as there is possibly no paperwork to show if the bike has been a dog to the previous owner