It's better to use the google maps in android auto as it is working well on my civic.
Since Garmin maps is not fully update for SL, using gmaps is the best to do the job.
Even though the android auto is blocked for our region in playstore, installing the apk directly is ok and i am using it for couple of months.
As I remember there was an expiration date for garmin maps subscription too, 3yrs or 5yrs.
regards