Ok, new plan, 10000000 times easier.
1) Pull the TAIL fuse,
2) Take ignition switched power off the fuse for pass. side bun warmer (not used by me anyway) and route to the exit of the TAIL fuse.
Should do what I want. Will report tonight.
UPD: works as good as one can hope for if one doesn't want to cut into factory wiring. The only drawback - you can't put fuse block cover back on. I might procure a spare cover and make holes in it later.
All you need is two of [ame="http://www.amazon.com/Littelfuse-FHA200BP-ATO-Add-A-Circuit-Kit/dp/B0002BGELQ/ref=pd_bxgy_auto_img_y"]these[/ame] (or even [ame="http://www.amazon.com/Bussmann-BP-HHH-ATM-Add-A-Fuse/dp/B000GKEXK2/ref=pd_sim_auto_1#productDetails"]these[/ame], can't figure out from the pic if this one has two fuse seats), and three fuses.
Connect wires of both tap-in adapters. Insert two fuses into the adapter that will go into the source of ignition-switched power (I used RH seat warmer). Insert one fuse into the adapter that goes in place of "TAIL". Pick one of the two slots so that there is no connection between the legs (as if original TAIL fuse blown) of the adapter. Don't remember exactly which way should the adapter go into the TAIL fuse, but if you get it wrong your halo lights will be off and your navi will be in night mode all the time. If that happens - rotate the adapter.
If your car blows up while doing this - don't blame me, lol.
UPD: quick picture added.
