It only records when motion is detected ahead, and automatically turns off when no motion. Remember loop is not necessary in this case!
Parking mode as you say, I agree!
I have had success with on G90c firmware! it supports both km / h & MPH / h
It is here: https://www.dropbox.com/s/j3uns6f44vpi2gh/GS90A%20MPH%2006082016%20v2523.rar?dl=0
1.coppy firmware.bin on microSD
2. Power supply for G90C
3. Select the volume "v" and wait for 100% complete renovation, G90c itself off
4. Disconnect the microSD card and restart G90c
Good luck!