I have been doing car audio for a while. I am goingto be doing a 2001 Sequoia soon and have read some things about it beig difficult to do. How can I tell if it has the Jbl 10 speaker setup?

It says Jbl on the front door speakers, has speakers in reR doors then 2 tweeters. That's all I can see speaker wise. Customer would like to be able to retain the factory head unit if at all possible. I was going to install new door speakers and tweeters and an sub and amp under seat and run all new speaker wire to the door speakers.
What would I need to do to bypass the factory setup if I use the factory head unit and like a PAC adapter?

Thanks

Sounds like the JBL system, not sure what you would need to bypass.