What is this contraption? It connects to drivers side control arm. I have to change ball joints, easiest way should have been changing the whole control arm but new part is missing that bolt hole. Other sides control arm does not have this... "thing"...

 

Welcome to the forum

FYI when asking a service question at least post your year and model trim of your Mazda?

 

Vehicle ride height sensor for automatic headlight adjustment

 

Good answer.