use a razor blade and slice a small slit the size of the wire in the rubber boot that the brake cable or throttle cable goes through, it may be easier to put the wire through the steering columb boot. after u put a slit in the rubber boot just push the wire through.
Connect the green wire to the brown striped black wire.
What year and what engine?
That is a body to engine ground wire.
Any wiring harness that passes through the firewall in a Cirrus will use a grommet. If you are adding a wire, snake the wire with the harness bundle to pass through the firewall.
Its on the firewall side of engine between transmission and engine just below the ignition coil packs one of the wire connectors from ignition module go to crankshaft position sensor
In my experience with my Chevy it was a ground wire
Through the wire harness bulkhead on the drivers side firewall.
The Chevrolet Cavalier CD player wiring diagram shows the beginning location of each wire and the ending location of each wire. The diagram is handy when diagnosing problems.
There should be a location where you can go through the firewall where other wires are already there. Piggy back on that hole. If not then just drill a hole through the firewall, being very careful not to drill into any wiring or components. Insert a rubber grommet in the hole to protect the wire, and then the wire.
I'm assuming you mean "hotwire"? Don't try it. You will fry the computer.
The Chevy starter does not have a ground wire, the starter grounds through the starter casing.
The spark plug wiring diagram for a 1994 Chevy Cavalier can be found in a service manual. The manual might be available at your library, or can be bought from most any auto parts store.