I had a knocking coming from the front left of the car. Took it to mazda and they said the sway bar linkages were shot so they replaced them.
I left the dealership, did one lap and it was obvious that they hadn't solved the problem, gg Mazda. So i took it back in and they replaced the front strut which has fixed the problem. So to all those getting knocks, get them to check your struts.