It depends on how you want to use it. What factory audio system is in the vehicle? If you are using it with a factory amplified audio system it will work great since it is designed to help flaten out low spots in the factory audio freq output. You will also need to know if the factory amp is internally x-over'd. If it is then you can't use one at all, it needs to see a full range signal. If your vehicle does not have the factory amplified audio system it will work, but it wont be as effective for its designed purpose. Also remember that the Aux input is only 2 channel(alot of people can't understand why the fader does not work when using aux). I have put a lot of these in and when set-up properly these work great.
The other way you can use it is as a Subwoofer interface instead of a high low adapter. Its not the usual for that applicationm but it sounds SO much better than a $20 interface.
There are better options out there with built in eq's and dash mount multi eq option controllers, but they are a bit more pricey.