I had one of my associates to do this product review for me and here are the results on the: Corux Smart 3 in 1 Bluetooth FM Transmitter with Car Locator, 2.1A USB Charger Vehicle Battery Monitor Hands-Free for iPhone 7.7 Plus Samung LG Huawei Mobiles.
Figuring out how to locate my car was a little tricky, but once I found the manually locate button on the lower left side of the screen, it was easy going from there. It will drop a pin on google maps so you can wander around until your heart is content and you will be able to see on the map where your car is located. If you happen to have no sense of direction, there is even a compass to steer you in the right direction and it even gives you the distance of how far away you are.
I didn't have a micro SD card to put into the slot so I wasn't able to test that function.
All in all this product does what it says.
The only drawback is that it isn't friendly for a phone battery. Turning the Bluetooth connection on seems to drain your phone battery, but if you're in the car and have it charging your phone you'll be alright.
My only concern would be after a long day of walking around, shopping, sight seeing etc. you might have a problem with trying to find your car with a low battery.