I was wondering if Toyota or an aftermarket company makes a stock upgrade to the 2013 Pioneer Head Unit for adding a subwoofer?

I'd like to keep things stock and not have to do any wiring. "SEARCH" on the forum didn't turn up much.

It'd be nice if you could just add the sub in the trunk and plug in to stock OEM pre-wire without running wires and adding an extra amplifier etc. but not sure if this is equipped?

 

I read somewhere that some people are replacing one of the door speakers to provide better bass. Would this be the easiest/cheapest route to go?