Does anyone know which of the four wires in dash go to front door speakers?

In any order for the 4 wires,
eg. 1,2,3,4 LtoR or RtoL
You can tap into 1or2, and 3or4 for your high level inputs to your sub. You can always use the phase switch of your sub amp 180deg if you are out of phase or just flip the high level input wires.

If you want to be more precise, get a multimeter and do the following and we can figure it out by deduction
1. Remove, disconnect and check the dash tweeter and trace the continuity from the connector pin to the pin where one of the capacitor is soldered.
2. Once you find the pin that is going towards the capacitor, that is the positive signal from the head unit, both 1&2 and 3&4 are shorted pairs depending which way you are looking at it.
3. Now mate the plug and the tweeter connector to identify which one goes to the pin with the tweeter capacitor (high pass filter), that will be your positive wire.
4. Now if you need to find which 2 wires goes to the front door, put your multimeter on impedance mode, it will be the wire pair that shows close to 3-4ohms measured from the wire connector that goes to the head unit (not the tweeter connector). It will be wire 1&3 or 2&4 depending which way you are looking at the connector.