So I figured it's easier t ask before i start tearing it apart and find out the hard way. Are there the wires to install an amp and sub on the factory radio? I know scion offers a sub what did they wire it to? And if they aren't there is it possible to add them? Thanks

 

No. The connections necessary to install an amp and sub are not in the xB from the factory. You will need to run a power wire of reasonable size from your battery to wherever you intend to mount the amplifier. You will also need a ground wire of the same size as your power, but it will need to connect to a clean, unobstructed ground point, with the length of ground wire as short as possible. The seat bolts are a decent ground point provided that all paint, carpet, dirt, etc., is cleaned and/or ground away from the connection point. For power and ground, do not use anything less than 8 AWG, and that is severely pushing it. I would use 4AWG for a single amp system, or 2AWG and up for anything more.
You will also need signal from your stock HU to the amplifier. Since the stock HU does not offer any RCA connections, you will need LOCs, (Line Output Converter) to convert the speaker wire connection to an RCA for the amp. These can be picked up at any stereo shop or online for a few bucks. Also remember, better quality RCA cabling=better sound quality. You don't need the HUGE $100 Monster Cable RCA cable for a small amp and sub, but you don't want to use those hair-thin $5 RCAs from Radio Shack either. Keep the RCAs and power/ground wires as far away from one another as possible. Power causes interference in the audio cable if it gets too close.
From there, you will need a remote wire to turn the amp on and off with the stereo. You can tap into the remote wire from the HU. This will work fine. Some people choose to add a switchable power wire for this, so they can switch the amp on and off themselves. The choice is yours. This wire does not have to be of considerable size as it is carrying minimal current.
Last, you will need speaker wire to connect the sub(s) and amp. This is fairly straightforward. Use reasonable wire. Too small a gauge wire or cheap wire will have more resistance and therefore will deteriorate the quality signal and could possibly heat up a bit. Good quality 14AWG wire should be just fine.
Something else to consider is this. If you are intending to create a fairly decent stereo system with multiple amps, subs, etc., you will probably want to go with an aftermarket HU to source it all. The stock HU is ok for "Average Joe", but it is not anywhere near audiophile sound quality. If you are planning to build a big multi-amp system, you are probably going to need a larger battery to support the power load, and possibly even a HO alternator if your stereo system is large enough to draw massive amounts of current.