Hello, I'm new here, have a 2004 Toyota Corolla and I'm looking to put a sound system in it. I'll need everything from the head unit to subs. I'm willing to buy some things used if not everything used. I'm not looking for the best sound quality but I am looking at it to be competition level loud, something that will really rattle the car. Any recommendations? Thanks!
where are you in florida?
spend most of your time researching how to properly install things, and spend the bulk of your money on having a custom enclosure built by a professional.
you can get pretty loud with just a ppi 900.5 and an efficient sub, plus it wont kill your electrical. $1000 is a bit low unless you're doing all used equipment while installing it yourself. id recommend just buying things slowly over time and being patient for the right deals to come up. the correct install parts do add up over time, id honestly recommend getting the headunit and 4 channel amp (the 9 wire conductor and amp kit) installed by a professional shop just because you're probably not the best at wiring (but i dont know that for sure).
id start out with a headunit like this:
https://www.crutchfield.com/S-Ak9299nMnLr/p_130X690BS/Pioneer-MVH-X690BS.html
and then get a 9 wire conductor run to where your 4/5 channel amp will go (id recommend in the trunk somewhere) along with a 4 gauge OFC wiring kit to power it. the 9th conductor is for remote turn on, by the way. then two/three sets of RCAs to run on the opposite side of where you run your power wire to provide signal.
id then invest in a dso nano digital oscilloscope for ~70 bucks to make sure you dont blow your speakers with clipped signal, set the filters on the 4 channel for your doors, replace your door speakers with probably something like a crescendo or prv pro audio mid and a silk dome tweeter.
and then get a sub like the cab ultra 12 and a ported enclosure built for it
youll save money buying used amps, but for door speakers and heaunits id just go with new unless you can get a pioner 80prs for $150 used
oh and the most important part of this if you're new to car audio is to do your research, and not to rush. you WILL be disappointed if you do things fast and set things up improperly, fail to terminate your wiring properly, etc.