You want to make it louder put some headers. Then it will be really loud. Lol. I did the headers and it's loud as shit. I'm changing the exhaust this week and then will post some pictures of the headers, exhaust set up and video. But that is the best way to make it loud and get performance gains.
New - 2013 - 320i - 15% Tint - Future Mods ( BMS Tune, Suspension, Wheels, Exhaust)
Sold - 2007 328i (3-Stage Manifold - BMW Perf Intake w/Scoops - Powerbox - Magnaflow Exhaust - MMW Headers - KW Street Comfort - VMR 701s 19' w/M3 offset - BMW Strut Brace - 330I Brake Conversation - 5% Tint All Around - 8K HID Fog Lights -Angel Eyes)