The security 'box' is to the right of the glove box, just above the outside kick panel. The plug is at the bottom, If you want to try plugging it back up to see what works. The security has nothing to do with auto door locks. Does the trunk lock/unlock with the key in either door? If not, then replace the 2 relays first. Junkyards are full of relays that will still work.

Junkyards also have nice glovebox doors, you would just have to swap locks so your key works.

The odometer is stored in the computer for the instrument cluster. Use OBD port A-7, push the black button 5 times, then 1,1,2 for the left 3 digits that get displayed by the blinking light. for the right 3 digits, 5,1,1,1.
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My back feels better when I sit in a Volvo seat