Progressively louder clunking noise coming from driver side footwell. 2013 Scion FRS
 

Hey, so when i bought this car back a few months ago, the noise was so small and subtle that it was easily dismissable, and was only audible at very low speeds while going over a bump in the road or a hole. Ive done coilovers, wheel spacers, short throw, CAI, and some cosmetics. After installing the short throw 2 days ago, the noise got consistent and very loud and obnoxious, and i first thought it was a CV joint or shaft, but after some research i figured out theres no cv joints in the front. What part am I looking for? I cannot find out what its called after a lot of research. I thought its called a U-joint but Im not sure.

Does it sound like it's coming through the steering wheel? There's a spacer in the EPS unit (which is down by your feet) that goes bad and creates an annoying clunking rattle. It's not super hard to replace on your own.

Also check nut on top of coilover is tight and sway bar end links.