Quote Originally Posted by THE KREEP
Can you run an aftermarket amp on an oem headunit in a 01 lexus is300?
I just want to add a aftermarket amp and sub with my factory HU, I am pretty sure it can be done....does anyone have any experience in this field and can anyone here do this?
Your stock unit does not come with Audio Outputs, so you can't just hook up RCA's directly to the radio. I know this is still true with the new IS and GS models. Which is weird because the new Scions do come with this. My 08 XB has Front/Rear/Sub outputs.

You need a Hi/Lo convertor. It taps into the speaker wires on your rear speakers and will convert that signal into Audio Outputs. They have both 2 channel and 4 channel ones. Then you just plug your RCA's into the box and you are good to go.

Just FYI, I sell several levels. The best quality one I sell is $10 for the 2 channel one and $15 for the 4 channel. I could also provide you with the T-Taps to allow you to tap into those speakers without any cutting. I will throw those in for free.