Just go into your Google Maps profile, choose Offline Maps, then Select Your Own Map.
Then when you're ready to find your car, just navigate to Parking Location in your Google Maps app.
Then go to Google Maps > Search Bar > Parking Location > More Info.
Just go to Google Maps > Profile > Settings > Notifications > Places, then turn on Saved Parking.
For most of us, navigating via Google Maps generally means entering an address and tapping Go.