I want to leave the stock headunit in the car since it has a 12 disk changer its a monsoon. I would rather use my alpine, but since they don't make a device to use the stock cd chnger I'll just keep the stock unit. Anyway I plan on replacing the front speakers with my component alpines and maybe run them with the stock rear back seat speakers, not trunk ones. I might run all four off of two channels on my four channel amp, or would this cause some problem since they are different ohm ratings? The other two channels will be bridged to run my sub. Yes I know this is not ideal, but I did this setup before, and it never over heated and sounded decent. What would be better, running the line convertors from the stock amp with one of those PAC things or running the convertors from the front right off the stereo with the RCAs running back to the amp. Also can you mount the cd chnager straight up, or must it sit as it was from the factory