So i'm going to do the DIY earthing on my sti because when i drive at night and indicate the whole dash/headunit dim EVER EVER so slighty, hardly noticeable infact but i know it's there and will wind me up no end - so how do i test the before and after?
all the new earths will be going back to a solid choc block which will have one connection to the battery negative.

Do i set the multimeter for resistance from the negative to the chassis before and after? minds at a blank

 

i havent done this - but - i would imagine, before....... You then have the resistance between negative and chassis - do your mod - check resistance again, hopefully the resistance would be lower............................

 

love to see some pics of your final earth setup mate