as for the constant power, alpine decks all say they must be connected to the battery. this is only what they recommend, I have installed them both ways and I promise you that you will not notice a difference.

 

how can you retain the console controls if you get an aftermarket deck?

 

do a search or talk to djqube there are many ways you can integrate with the factory controls.

 

Radio Installation products

Check here for the various Dash Controller Units. Multi-Radio DCI is the best unit you can buy

 

I second the Lucid DCI. I have it installed with the alpine CDA-7894. This is the best interface for an Alpine deck! worth every dime.

Lucid has the right harness for the S2k and other shops just have one that will work, but you lose the Mute and Dash Control connection. I had to find out this fact the hard way.

 

I also highly recommend the Multi Radio DCI, I have it on my 03 S, I'm using an Alpine 7995. It works beautiful. It's very easy to install and there is no programming needed. The one that crutchfield sells you have to install and then program the features. The DCI already comes pre-programmed and it add much more control features than the stock control was giving you before.

Hope that helped.