ELM327 ODB2 scanner casing with reset button

Recently, i bought a cheap OBD2 scanner for my car with bluetooth connection.
It's the cheapest one on ebay right now for about 3.50 USD

search ebay for "ELM327 V2.1 OBD2 Bluetooth Scanner"

With this, your smartphone running the Torque app (or another OBD2 app) you can
view various realtime data from the vehicle, view error codes and reset error states.

I wanted to leave the device plugged in to the car, but because de device is always
supplied with 12V, even if the car is parked, the module keeps drawing 33mA current.
This cheap one does not seem to have a sleep state.
(note when transferring data, the amperage rises to 65mA max)

I've seen some solutions on the net to hack the OBD2 connector in the car, to make it
suppy the 12V from the accessories so it's only on when you turn the key.
This can be very tedious to do depending on make and model of your car because the OBD connector is mostly hidden somewhere under the dash.
But why alter the vehicle when hacking th