Yea I read it but the way it's worded it sound like it's contradicting itself.
"The empeg ships with its own ISO wiring adapter in case your car doesn't have an ISO connector and you still need to solder the wires. In that case, you can either cut off the empeg connector and do it like any other car stereo, or you can use their ISO adapter. If you use their adapater, the connections will go like this:"

To the best of my knowledge in order to use the iso connector for each car makers you would indead have to cut the empegs iso connector off in order to connect the you bought with the dangling wires on 1 side and the snap on connector on the other end that connects to the car.

Blue MK2 20 Gig, Slowly getting filled to the brim.