[Hardtopz28]

I recently bought my wife a m3. Well we have no idea what it can do. I'm a gear head but this car is not a mustang or a camaro. The car is a 2008 m3 with nav and paddle shifters. We picked it up for 39k and I must say its pretty badass I have a couple of question...... How do I get a extra key made. 2. How do I get sat radio 3. What mods is a must do 4. What does the button behind the shifter do the one with the up and down arrow. Thanks for any help