(Too long didn’t read version: If you have a top of the line vehicle, great, this interface is necessary.
If you have a base model, it’s still necessary, but only for the 22 pin adapter it comes with, the $99 interface you’re paying for does essentially nothing for you, but you don’t have a choice, you can’t install a radio without it. So it’s basically a $6 adapter harness with a $93 interface that’s absolutely useless to you if you have a base model vehicle, but they’re not sold separately...so unfortunately you still have to buy it.
Does it work? Yes it works great. Is it overpriced for those of you who have a base model? Absolutely.)
So I found out the hard way that I could NOT install an aftermarket stereo in my 2007 Caliber without this.
If you have steering wheel volume controls, navigation, amplified speakers, microphone...etc, then great, you’re getting the best bang for your buck.
If you have the base model Caliber? Well, tough luck, 80% of the wiring on this harness doesn’t apply to you and you’re going to have to do a ton of wiring work to bypass the interface being that you don’t need it at all. (That’s right, $99 but no plug and play here folks!)
Essentially, if you have a base model vehicle, this $99 interface is good for about 3 wires, the remaining wires, you’ll have to bust out your wire cutters and wire up the old fashion way.
Is there any way to bypass the interface? Yes. And if you don’t have an amplifier, you’ll be bypass every speaker wire...manually.
What actually goes through the interface? Your ground and power, and a ton of wires that are useless to you if you have a base model vehicle, everything else, you wire by hand.