Lexus 2002 GS300

I am about to do my first GS RS and I had a question.  The only part of this install im concerned with is the functions that are controlled by the factory alarm key. The sunroof and windows. The customer wants to know if I can make all that work with the aftermarket alarm, or will his old key remote still work. What is the best way to deal with this without having the alarms interfere with each other. Is there a certain duration that i need to pulse the lock wire for in order to make the windows and roof roll up?

thanks for all your help.

my documents state that you will have to add a window module to get the two front windows to work with an aftermarket system.  The sunroof is not recommand.  What i would do if was you would be to see if the features that you are refering to work when the car is running.  If they do, then just tell the customer to use the factory keyfab.  If they dont.....you can get the 2 front windows to work but the sunroof is not recommanded.

You will need to tap into the wire in the driver door. If you put the key in and hold it to lock, it will close all the windows.

I think it's possible with a timed output. Not sure on the details.