if the sub box is carpeted and your boot floor is carpeted, you can do what I did. Go to bunnings and get the heavy duty velcro hook strip, $18 from memory.. works like a charm and fairly easy to take off if you need to... and use a button head screws to fix the velcros to the sub box...

as for the wires, I suggest you go to jaycar and get a new pin connectors (maybe for all the pins while you're at it) and make a new crimps for all wires and then stick it back in the socket..