I get a clicking/knocking sound from what sounds and feels to be coming from the front left tire of my Impreza. It happens when you just first starts moving (either forwards or backwards) or when you first touch the brake while moving. It will only happen once each time you touch either gas or brake. It will do it moving in a straight line, so doubt that it’s CV.
The guy that I bought it from upgraded the sway bar, end links and bushings so all those pieces are new-ish. I’ve taken it to a mechanic who did a cursory inspection and said that all suspension components looked ok and were tight. He also confirmed that the boots looks good on the CV joints. I’ve also confirmed that all lug nuts are tight, so it’s not the wheel moving.
The other curious thing is that I cannot recreate the noise by manually bouncing the car up and down or rocking it back and forth while the car is stopped - it only happens when driving.