The “proper" way to wear a seat belt is to have both the lap and the shoulder belts in front of your body not behind it.
“Failure to properly wear a seat belt”, and unless your seat belt was not working at the time, is always written as a “non-correctable” citation.
Traffic school is not an option because the violation carries no points. So to take traffic school to get rid of zero points would be.... pointless. Or should I say “useless”.
Feel free to contest it... But unless you can somehow prove that you were “properly” wearing your belt then you're not gonna get far enough to get it dismissed.
All convictions are reported to the DMV; this one, however, is reported as a non moving violation and one which should not affect you insurance premium.

