2001 Monte delayed power?

I'm installing a new head unit into a 2001 Monte Carlo LS and the Metra wiring harness comes with a note saying that a switched power lead does not exist in the factory wiring harness (i'm guessing the computer tells the factory radio when to turn "on" over the data bus lead in the harness). 

What i would like to do is to retain the delayed radio power option that the factory radio has with my new Kenwood head unit.  I was thinking i could do this by tapping into the power windows - which are still hot after the key is turned off and until the doors are opened.  i figured i'd tap into the window switch supply and use that lead to energize a relay with a fused power source direct from the battery.  that way the current draw from the relay shouldn' t blow any factory power window fuses - which it "could" if i hooked the new radio up directly to the power window lead.

My main question: where is a good place to tap into the power window lead?  can it be done in the driver's kickpanel area or under the dash without pulling the door panel?  i'd really like to not have to pull the door panel and trace wires.  or could i just pull the switch?  (just thought of that as i'm typing). 

since neither Haynes nor Chilton has bothered to publish a body manual for this vehicle yet, i'm kinda reluctant to start pulling off panels - i never know if it's held on with a hidden clip which will pop off OR a hidden screw which will snap off a panel tab somewhere!

thanks!

Your plan might work, but if the GM off-delay is like the Ford off-delay, the circuitry is inside the Visteon head unit not from the computer.  You will probably need the Chevrolet factory wiring diagram for the car, which can be purchased through any dealer for about $40.

i looked at the Metra GMRC-01 harness on several websites and it looked like all it did was retain the factory door chime.  i don't really care about the door chime as much as the computer interface.  i did not see any provisions on the harness to relocate the factory radio so i can retain my computer settings interface.  i DO have the Metra 70-2003T GM 2000-up Class 2 Data Retention Harness and inside on the instruction sheet it says "Due to the fact that a switched 12-volt accessory lead does NOT exist in the factory harness, an accessory source must be located."  that's what i'm trying to do. 

the windows are hot while the factory radio is hot - even after turning off the key.  i figure they must use the same singal source for time delay.  i also figure the power window relay (switched by the computer?) can handle the tiny current load of another relay to power the required switched accessory lead for the aftermarket radio.

i'm just wondering if anyone who has worked on a monte could help me out with locating this one wire...

on another note  though: since the factory system has an outboard amp in the trunk, am i correct in assuming that i will either have to: 1) drop my speaker leads from my Kenwood down to linelevel to interface into the factory harness at the dash, 2) bypass the factory harness/amp and run wires directly to the factory speakers, or 3) use Kenwood linelevels and aftermarket amp and speakers (this was intended to just be a headunit swap - not an entire system swap)?

Thank you chrisswallace187 for the clarification.

Now, if you have a factory amp in this vehicle and you want to make it an easy install, use Metra part# GMOS-03 instead of the GMRC-01. It is the same piece except the GMOS-03 will interface your factory amps for you.

Recap; GMOS-03 WILL keep delayed accessory feature.

              GMOS-03 WILL interface factory amp.

              GMOS-03 You DO NOT have to keep the factory radio in the vehicle.