So we can agree that mosfets, both N and P channel, are available that will work at 3.3V, as described in posts #6 thru #8.
I agree with ronv (post #11). We should concentrate of the circuit. Maybe a transistor driver is needed, but that seems to get us back to the other thread.
I am not sure a transistor driver is needed, because I am not really sure what the OP wants out of this thread. PIC's and other MCU's can certainly drive small mosfets directly, particularly when the switching speed is not critical.
Given a 12V supply to the latch and a 3.3V mosfet, the simplest solution for a switch might be an N-channel mosfet (rated at ≤ 3.3V Vgs) sinking current from the door latch.
John