Best speaker placement for 57

I'm trying to piece together a sound system for my 57 two door. My big question is what would be the ultimate best speaker locations? I built two 10" sub enclosures for the trunk and plan on two 6x9 on the rear deck, and 6" rounds in the lower doors. What about tweeters or extra speakers? I am building a custom headliner and full length center console so I can add speaker to these location.
What suggestions do you guys have?