i have just got myself a mazda3 2.0 sport, and under the bonnet between engine cover and battery compartment there,s a slim rectangle shaped box, the cover is missing, what is this part called so i can order the cover, i know some of u must be thinking wot a lemon, but i,ve mainly had motorcycles, not had much experience with cars, if you can help thankyou and hello. oh and it,s the model with the lf and l3 engine.

 

It's the box for the ECU. Not sure what the part itself is called, but that's what in it.

 

thankyou,