Green cable coding usually means live with ignition on. In this case it could be the unused heated seat feed. Easy to check with voltmeter. The map light wiring is already in loom though. Look for unused connectors brown/green and black routed from power socket cabling.
Front loudspeaker cabling is also part of wiring loom and can be found behind footwell panels where speakers are factory fitted when spec'd. Black/white and black left hand side, black/red and black right hand.
