There are no standard speakers in the back. anyone know how to get some there? also, how do you change the head unit when the standard cd player seems to be completely separate from the display? The car is a 2001 SR model and the sounds are crap!!!!

The head unit you have is either in 2 or 3 seperate units. Its either a double din or triple din, you cannot remove the head unit and replace it with a single unit,as you will have ugly open spaces, you could fit a dvd screen unit to cover up the spaces, thats your best bet. Speakers in the parcel shelf at the back are easy add on's. You may have to replace the back board or cut holes into the original. But yeah the peeps above are right. Your best bet will be a sound install shop. Yaris's can rock with the right equipment.

go to an auto sound shop and have them do it

best advise i can think of 4 u is to bring it to a stereo install shop and have a custom setup put in by a pro good luck