Upgrading audio

The front speakers in my 2010 Aveo LT Sedan have tweaters. What size are they and (although im pretty sure they are) are they already setup with some kind of component system? If for some reason they are not will they still work fine with another deck?

I have searched but just making sure is all. Front speakers are 4" and the rears are 4x6s? Correct?

What do some of you think of the 6.5" in the front? Is it necessary to make additional holes for it or is the 4" area good enough?

Thanks

if you go 6.5", you'll need a shallow mount speaker. as far as the tweeters, if i recall correctly, they just feed off of the front speakers. and may have a built in filter but i'm not definite

Got some Pioneers 6.5" that fit nicely with the spacer. no window issue at all.

If anyone else could give some more info regarding the tweeter setup, id really appreciate it.

Attachment 5283Here's the schematic