CardView background color states not being respected

Though this is not ideal, since the edges are not rounded, you can add touch feedback to a CardView like this :

<android.support.v7.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:cardCornerRadius="4dp"
    android:clickable="true"
    android:foreground="?android:attr/selectableItemBackground">

    //Nested View ...

</android.support.v7.widget.CardView>

Adding the android:foreground and android:clickable attributes to the CardView.

Also this has a negative side effect in that the android:clickable attribute overrides any clickListener, and therefore those clickListeners don’t get triggered.

Update

I have some examples of CardView implementations

Loop (https://github.com/lawloretienne/Loop) –
https://github.com/lawloretienne/Loop/blob/master/app/src/main/res/layout/category_card.xml

QuickReturn (https://github.com/lawloretienne/QuickReturn) – https://github.com/lawloretienne/QuickReturn/blob/master/sample/src/main/res/layout/activity_quick_return.xml

Update 2

After more research I have come up with a good solution for CardViews on all API versions including pre-Lollipop.

https://medium.com/@etiennelawlor/layout-tips-for-pre-and-post-lollipop-bcb2e4cdd6b2#.9h0v1gmaw