Is this a proper way to test for proper ground?

Newbie here,

Is this a proper way to test for proper ground?

I have finall started my first install and want to make sure that it is properly powered and grounded. For power I used a scosche 6 ga amp wiring kit with inline fuse (fuse approx 1 foot from terminal) For my ground wire I used a 4 gauge wire. I had trouble picking a grounding point in my 2005 legacy i. I settled on a strut bolt in the trunk of the vehicle. Before attaching the wire i cleaned the area down to bare metal. I also cleaned the bottom of the nut to clean metal. The ground was then connected.

Before i could check the ground i had to do some internet research as i am no electrical genius. I checked the ground by using a digital multi meter set to ohms. I put it in the 200 position and touched the leads togeter for a reading of 0. I then got a and tested an 8 ft section of 10 ga (red lead to one end and black to the other) wire for a resitance reading of .6. This wire will be used to create a jumper from the battery ground wire to the trunk. I disconnected the negative battery tereminal wire and ran the 10 ga which was connected to the vehicle ground wire to the trunk. I then used the digital multi meter with one lead attached to the jumpered vehicle ground an the other lead attached to the newly installed 4 ga trunk ground. I got a reading of .09. From what i have read you should subtract the resistance of the jumper from the trunk ground which would be a reading of .3

Does this make sense or am i way off base here?
Is that a good reading?

The way you ground your system depends on what your trying to accomplish, most people do not run a ground wire all the way from their battery to the trunk. If you connect the ground to the chassis of the car, (depending on the typical polarity of the vehicle) this is considered a good way to ground a system. To check the system ground, check the amount of ohms between the battery ground and the ground point you used in the trunk. This will give you an idea of how good the ground you used actually is.