I've had a textbook set off the passenger seatbelt gong. Weighs about 5 pounds. A book is a little over the top for sensitivity but a cellphone is way over.
2015 F30 335i | M-Sport | Estoril Blue | Black Dakota | 6-speed | HK Sound | Cold Weather | Premium Pkg | Sill Decals | Coded
| 19" Style 442M Grey Orbit Staggered | M-Sport Brakes | MPPK | MPE | Front Splitter Black | CF Rear Spoiler | Black Grilles
Previous loves: 2013 F30 335i / 2009 E90 335i / 2007 E90 328xi