Octavia II FL VRS Estate Speaker Upgrade (Again)

Hi all,

Done a lot of searching and and found a lot of conflicting info... please help;

1. Do the speakers need drilling out from their rivets?

2. Are the front and rear both 16.5 or are the rear ones smaller?

3. I have 4x 16.5mm Alpine speakers and SAK 3103 adaptors that I removed from my Leon FR before I swapped it. Can I put 16.5mm speakers in the rear doors with these adaptors?

Is there anything else I need?

Thanks,

Phil.