JL C2-350X 3.5in Dash Speakers
Just installed JL C2-350X in my 2015 SR5 (non-JBL) and I am completely blown away with how amazing they sound! They are powered off my Pioneer AVH4000-NEX head unit. Got them for $58 on Amazon, Money well spent!
Install was very simple, cut the factory wires and used quick splice connectors to wire the new speakers. I wired them with a 300Hz Bass blocker to the positive wire.

Factory dash speaker and wires- cut all 4 wires on each speaker, and twisted each Pos. & Neg wire together.

Used Male & Female quick splice connectors
Bass blockers wired to the Positive side on each speaker

I used these small little metal plate brackets (just a straight strip of metal w/ 3 holes in it) and they worked perfect! Only one bracket needed per side, then pivot the speaker so the holes line up. Also, surrounded the speaker with foam to prevent any buzzing.

Used a dremel to shave off the plastic ring on the inside of the dash cover, this prevents the speaker from contacting any plastic.