XML : My recyclerview is overlapping my toolbar. How to fix?

I am using AppCompatActivity so I am using a toolbar.

Basically, I want the toolbar to be fixed and everything to come below the toolbar - but this is proving troublesome.

This is my xml code:

  <?xml version="1.0" encoding="utf-8"?>  <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"      android:layout_width="match_parent" android:layout_height="match_parent">        <include          layout="@layout/toolbar_custom"/>        <android.support.v7.widget.RecyclerView          android:id="@+id/carRecycler"          android:layout_width="match_parent"          android:layout_height="375dp"          android:layout_gravity="center_horizontal|top"          android:layout_alignParentStart="true"          android:layout_alignParentTop="true"          </android.support.v7.widget.RecyclerView>    </RelativeLayout>    

Even when I try manually moving the recyclerview underneath the toolbar - the app crashes!

Would mean a lot if someone could help me out

Thanks