4 + 4 Ohms =......I'm not sure

[Pdwight]

Well the linear DC answer is 2 Ohms......but... I am pretty fair electronics person and I know when to ask and take advise. I have a pioneer head unit in my car and am driving my crappy rear speakers (one on each side) directly from the head unit( Pioneer like I said)
I ordered a set off the metal rear speaker brackets to replace the Porsche Plastic ones in my car and going to ditch the cheapo speakers. I just got in 4 of the Polk DB351 that fit the brackets like magic. They are listed as 4 Ohm each.....so the real question is parallel or ??

Thanks in advance

Dwight