What you are confused about, let me answer them one by one???
Q1: Will this charge while having an otter box cover or pop holder on the phone?
A1: No. The induction distance between the wireless car charger and the smartphone cannot exceed 4mm. Thick phone cases and pop holder will interfere with the wireless charging.
Q2: Will this provide 10W fast charging for the Pixel 3?
A2?Yes. It?s also working for these phones:
iPhone: 11 Pro Max/11 Pro/11/XR/XS Max/XS/X/8 Plus/8
Galaxy: S20/S20+/S20Ultra/Note10+/Note10/S10+/S10/Note9/S9+/S9/S8+/S8/Note8/S7 Edge+/S7/S6 Edge+/S6 Edge/S6+/S6/Note 5
SONY: Xperia Z3v(D6708)/XZ2/XZ2 Premium/X23
LG: G2/G3/G6/G6+/G7/G7 ThinQ/G7+ ThinQ/G8/G8 ThinQ/V30/V30+/V35/V40 ThinQ/V50/V50 ThinQ/LG Lucid2(VS780)/LG Optimus FS(AS780)/Optimus Vu 3/Optimus G Pro/Optimus VC11/Optimus LTF/Stectrum 2
GOOGLE: Pixel 3/3XL/4/4XL
Q3: When I turn off the vehicle(car power), can the holder’s arm be released automatically or manually, so I can take my phone out?
A3: Yes, you can remove your phone by pressing the side buttons after the vehicle is off. (It is recommended to remove the phone immediately, or the arm will not work due to the delay).
Q4?Does this charger turns off when the car engine is turned off? Will it drain my car battery if left plugged in?
A4?No. When the car engine is turned off, the charger will also be turned off and the power supply will be disconnected.
Q5: What is the point of wireless charging? You still need to plug in the mount. What am i missing?
A5: The phone is wirelessly charged through the mount, but you still need to draw external power via cable. You don’t have to finagle to hook up your phone to a cord every time or worry about the port being damaged.