Amp install question

I'm going to install some new speakers and an amp using my stock HU. What do I need to interface the amp with the stock HU? Does someone make a plug and play type?
I have an 03 double cab
Thanks in advance!

 

You're going to need a line output converter. It's not necessarily "plug and play" but it's pretty simple. Some some basic splicing is all that's needed. What it does is takes the speaker wire output from the deck and converts it to an RCA style output. These are used for decks without pre-amps (i.e. the OEM deck).

Here's a four channel one on crutchfield. They also make two channels as well.

http://www.crutchfield.com/p_142SLC4/Scosche-SLC4.html?search=line+output+converter

Let me know if you have any more questions.