I'm in the process of ordering a new auto dimming mirror for the drivers side of my car. It seems there was a couple of different types for my year car. One of the mirrors has a brown and a blue wire that go to the top and bottom of the mirror connected by a square plug. The other has a round plug that plugs into the lower right corner if you are looking at the back of the mirror. My car has the round plug. The mirror I'm looking at buying has the 2 wire/square plug. The guy I'm buying it from said that he thought one wire was for heating, the other for dimming...but that can't be so. There would need to be 4 wires instead of 2 if there were 2 loads...1 for supply, one for return (ground). At any rate, with the plug difference, can I make this mirror work for me?