From the sheet metal to the window track you have 2 inches. Now, the rest of the speaker will have to fit between the sheet metal and the door panel. I don't know if the door panel will fit back on there with such a deep speaker. I mean, the door panel will fit back on there, but the area where the speaker is may not fit well.
You will probably need to make two 3/4" MDF rings for EACH side, but I have worries about the door panel fitting properly with those two rings.
What speakers are they?