hey mate i have pioneer 6inch (6.5 if picky, but no difference) 3-ways in my parcel shelf, they are easy as to install and sit right into the original holes, i'm guessing that all brands 6 inch speakers would fit straight in aswell. the speakers are excellent and u wouldnt know they were there (if it wasnt for the increased amount of noise and rattling the panels do). oh and the original wiring can be used u just have to put smaller terminals on, your choice.
Need some parts for my VH 253:
Green standard steering wheel...Green lower B-pillar covers.
Green sunglasses holder/lower dash bits...Air-con and assorted engine bay parts.
PM with any info.