Finally, a factory amp wiring diagram
 

Many people have messaged me about the wiring diagram for the factory amp, so here it is. Courtesy of Mike West of JL Audio.

http://i53.tinypic.com/1z4b9xe.jpg

Is it possible to bypass the actory amp without losing blue tooth / nav capabilities?

as in.. switching out head units and using the factory amp?

No you can't bypass it.
Even volume control passes through the amp.
You can only take high signals from the amp and pass them through an aftermarket amp with high to low converters.
Audison BITONE is the best for the job.

^ Oh, i thought you were able to bypass. Right now im running aftermarket speakers and subs going through a 4 channel amp to a sunning device straight to my stock oem head unit. I just wanted to make sound quality even better. Oh well.

You can make it sound better
https://www.clublexus.com/forums/is-...ml#post5640637

my question is.. what kind of summing unit and what amps/speakers? in the end you get what you pay for

Is this the same pinout for the 07gs350?

can i I use my stock amp with an aftermarket head ​​​​​​​unit?
 

can i I use my stock amp with an aftermarket head unit?

Yes, providing you get a wire harness from Beat Sonic or the Scosche dash kit. I replace my stock radio via the Beat Sonic harness (2007 IS250 without ML) and the sound quality along with the volume improved significantly. In my current setup, I bypass the factory amp.

Anyone wondering for the tweeters, they are pink and purple wires wired from a crossover from the midrange speakers. Then from pink/purple they go to a clip changing into gray and black wires.