Not sure if anyone else has had any issues with their seat belts, but the stock magnets were simply not strong enough to hold the seat belts in place. It was an extremely annoying issue which I am thankful to have resolved (credit it due to some random website/poster which I cannot find at this time)
Luckily, I was able to find some magnets which I was able to add on and strengthen the hold on the strap for the seatbelt. The magnets were cheap, not noticeable and did the job. Here is a link to the magnets which I got on Amazon. http://www.amazon.com/gp/product/B001KUN5J2/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
(you may choose to glue them or let them rest)
Again, I found this on another website, but was unable to find any information on this subject on this forum, so I figured I'd share.
Let me know if this works for you as well!