ohms query....yes another one

Hey all,

Here's what I'm thinking;

I have two component sets I'm installing in my Jeep(rear=2x8"woofer + 2x4"mids + 2x1" tweets+2x three way passive crossovers)( front =2x5.25 mids + 2x1" tweets+2xthree way passive criossovers) +(2x2channelamps) 

I'm thinking that I have enough rear fill(the speakers are mounted in a box 12" behind the seats.  The 8's are in sealed enclosures and the mids are free air.  The front speakers are in the dash,free air. 

 I think I won't have a great front sound stage.  My query is that if I add another pair or two of two way speakers in the front(doors, or more likely kicks) and hook them up to the crossovers along with the "original" crossovers, how will the amp see this re; ohms.  All the exhisting speakers are 4ohm.  As I understand it, the amps will be seeing 4ohms using the "original" speakers and the xovers.  Any suggestions will be appreciated.

Very astute answer, thank you very much.  Amp is 2ohm stable so all is well.

-JM-