How many times have you parked your car in a large parking lot like the mall or a theme park and forgot or were not sure where you parked your car. Did you remember where you parked in that long term parking lot at the airport?
Do you have a cell phone that can take a picture -- do you know how to use it to take a picture?
Snap a picture of the car in the parking lot with some landmarks or signs that you will recognize. You can always refer to the photo if your mind was on something else when you were parking.
You even have a photo of where the car is parked if you have to tell someone else where it is parked to go get it. Simply send the photo via text or email to them.