For the R/S Chassis Ground connection you want a very "solid" ground. Obviously the best
choice would be with a soldered on terminal lug connected to the (-) battery terminal. That
is typically overkill. If you look around for a convenient location under the dash, near
where the R/S unit will be placed, you can usually find a Factory ground point where
several factory wires are bolted to the frame of the vehicle. You could use that connection
point with a soldered on terminal lug on the R/S ground wire. Basically any solid frame
location will work, I try not to drill holes in the customers cars but there are times
when it's necessary. Usually there is a shiny 3' diameter pipe under the dash across the
vehicle that is a solid ground point. You could drill a holes in this pipe and then use a
self-tapping screw to secure the R/S ground wire ( with a soldered on terminal lug ).
Last choice is to find a convenient location in the firewall or kick panel, use a wire
brush to remove the paint and then a self-tapping screw through the soldered on terminal
lug of the R/S's ground wire. Just ensure there is nothing on the other side of the metal
panel that the self-tapping screw will hit. Here are some ground location photos :
For the cut Green/White Immobilizer Data wire, just follow the guide. You're over-thinking
this install. The "vehicle side" and the "connector side" are exactly what they mean. On
the Install Diagram, if you drew in a Green/White wire from Pin 2 of the illustrated
connector, through the "IMMOBILIZER (DATA) GREEN/WHITE OR GREEN/PURPLE- 02" description
to the cut wire diagram, that is exactly how you want to make the connections. The DC3's
Green and White/Red wires get soldered on to the cut Green/White wire going to the
BCM Green connector. The DC3's White/Black wire gets soldered on to the side of the
cut Green/White wire going somewhere into the vehicle ( sometimes called the "away side").
Additionally, I always join those two DC3 immobilizer "connector side" wires near the
DC3 and just continue one wire to the cut wire connection point. Makes things neater
and electrically / logically, it's the same.
Soldering is fun!