To answer many of the questions about how to wire in an aftermarket head and use the dash tweeters W/O having to use the factory amp, I will post the wire colors on the infinity plug to facilitate bypassing the amp. You may inherit a car that has an aftermarket head and does not have the amp any more and need to rewire etc....
Ideally you will have some type of crossover to protect the mid and tweeter in the front.
Please note that the factory colors for the Rear and tweeter on each side are the same so you will need to "pop" the speakers with a 9v or drill battery to determine which set is which. If you do rewire, you will need to disconnect the wires from your headunit/ adapter harness, and instead feed them down to the passenger floorboard where you will be tying into the factory after amp wiring.
Left rear
+ yellow w/ blue
- gray w/ blue
Left front tweeter
+ yellow w/ blue
- gray w/ blue
LF Mid
+ white w/ blue
- black w/ blue
Right Rear
+ yellow w/ red
- gray w/ red
Right front tweeter
+ yellow w/ red
- gray w/ red
RF Mid
+ white w/ red
- black w/ red
Here are some pics I took with my $19 digi camera. Note that this is mid install before all wires were tied down and hidden and the crossovers mounted. Best of luck and as always test everything for correctness. this is what worked in my particular car. I don't claim that every car is exactly the same.
Infinity amp Wiring Colors (bypassing)
