That is indeed a welcome move from Google Maps. This will help you finding your parked car in huge malls. To use the feature, you need to be signed in to your Google account. Once you park your car, tap on the blue dot and choose the pop up. You can save additional details like when would you want to be reminded of your car. You can also save a few photos of the surroundings so that you can remember the location better.
The feature appears to be available on the beta version of your Google Maps on Android. It has not yet been made available for iOS users.
The feature is in sharp contrast to a similar feature on Apple Maps. However, unlike Google Maps, the Apple's solution needs your iPhone to have a bluetooth connectivity with your car. The feature from Google Maps seems to be more practical.
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