Are base model 3rd Gen's wired for rear speakers?

I want to add rear speakers. Wondering what size speaker / grill cover I need and if they are pre-wired. Thanks for any advice.

 

On the sienna it just depends on what floor wires are put in. Sometimes option wires are there and just taped up and sometimes not at all.
like a sport model comes with manual rear window vents, no blind spot monitor but has other high end options. They will just tape up the wires not used.
A base model with not have any extra plugs. Its a bare bones wire harness.