Would like to mount a small SubWoofer with brackets and sheet metal screws which come with it behind the passenger seat against the near vertical carpet covered metal surface the passenger seat would back up against -- Does anyone know exactly what is directly behind the carpet in that area ? Any chance of damaging a critical component or wire harness behind that surface with the screws protrusion ?

Also, looking for some ideas of where to run new wiring between the rear Speaker location up to the front stereo area without drilling holes if possible. Any suggestions from folks who have done this speaker upgrade is appreciated.