diff --git a/source/_components/device_tracker.automatic.markdown b/source/_components/device_tracker.automatic.markdown
index dff0b45fec9..f3e63a648dd 100644
--- a/source/_components/device_tracker.automatic.markdown
+++ b/source/_components/device_tracker.automatic.markdown
@@ -56,5 +56,8 @@ automation:
     action:
       - service: light.turn_off
 ```
+<p class='note'>
+  You can obtain the correct ID for your vehicle from your known_devices.yaml file. Be sure to lower-case any letters contained in your vehicle's ID when using it in an automation trigger.
+</p>
 
 See the [device tracker component page](/components/device_tracker/) for instructions how to configure the cars to be tracked.