Ok, so a little more detail. Idea is to improve the path that the current to start your car takes, so that means from the battery to the starter motor and back around to the battery. We'll just ignore the fact that current actually flows from negative to positive, electrons being negatively charged and all.
Looks a little like this, in ASCII art for those that remember such foolishness:
+Battery --> Starter solenoid --> Starter motor --> engine metal --> body metal --> -Battery
+Battery --> IPDM --> ignition switch --> starter relay --> starter solenoid --> engine metal --> body metal--> -Battery
In both cases you see the 'engine metal' play a part. As you may recall the engine (made of steel and aluminum, both conductive materials) is supported by rubber engine mounts, which are non-conductive. To provide a high power path for the return currents generated by the alternator or used by the starter motor, then engine has a conductive connection to the metal body of the car (chassis) which then has another conductive connection to the negative terminal of the battery. Either one of these can go bad.
The engine to body connection on Gen3's is part of the negative battery cable that extends between the metal body work and transmission housing (driverside), under the battery tray. Usually the connection between the engine and the battery goes bad due to corrosion/mechanical fatigue at the mid-crimp point (battery to chassis) or the end crimp (battery to engine) connections.
The body to battery connection is just the black cable you see attached to the -ve terminal of your batter which goes a short distance and terminates on a bolt into the body sheet meta and then on to the transmission housing. Often the problem here is corrosion between the terminal and the body metal, or corrosion within the wire jacket itself.
The hack is to replace both of these electrical connections using something 'handy', like jumper cables (which anyone with a car or battery over 4 years of age should have). In this case instead of connecting two batteries in parallel, we are creating a Y connection from the battery negative to both the engine/transmission block of metal AND the body. You are looking for a large bolt head, or thick metal bracket that obviously is securely fastened to the main bulk of the engine/tranny metal. For the body connection, the 3 nuts used to hold the strut into the tower make a good and convenient choice.
For safety reasons I would do this in this order:
1. black jumper1 connector to battery -ve
2. black jumper2 connector to engine/tranny
3. red jumper connector1 to black jumper1 connector attached to battery -ve
4. red jumper connector2 to strut nut.
EDIT if you need more slack lead between the #2
terminals you can safely split the wires further than they came from the factory. I would do it while the plastic is warm AND pull wires towards and away from you with the join between instead of just pulling them left and right as there is less chance of the insulation being torn from the side of one of the wires. You get better shearing action on the thin bit of plastic by ripping 'through' it instead of 'across' it.