Have you ever lost your car at an airport (remember those) or a giant car park? If you have location turned on on your phone, you can get Google to remember. 

• Touch & hold the home button or say "Hey Google"
• Say (for example):
• "I parked here", "remember where I parked", "I'm parked in level 3 row 3", "I'm parked in the blue zone"
• When you get back and are wandering say "Hey Google - where did I park?"

Google will tell you. It'll even show you a map!