Had time yesterday to put the 6mm spacers on the rear of the Audi, as the rear wheels were just a little too far inwards compared to the fronts.
Here is what I did to check and confirm size of the spacers I needed. (I am sure people have various different methods of doing this, but this worked for me
1. Using a piece of wood and 90 degree level/measure, I checked the rear and front clearance against the tires (if you have stretched tires, you would check against the edge of the wheels/rims)
You can see here on the rear wheel, (using wood against tire to the arch), there is room to push the wheel/rim out
You can see here on the front wheel, (using wood against tire to the arch), there is no room to push the wheel/rim out.
I now using the 90 degree level/measure, I measured to see what required spacers I needed. As this level/measure didn't have mm on it, I marked it and then used a smaller measure to confirm that the spacer was 6mm, thus I ordered 6mm spacers from ECS Tuning.
So with parts arriving last week, time to get on with the install
I Jacked up the whole rear of the Audi (loosing bolts first while wheels on ground) and then once wheels off ground unbolted lug bolts and security bolt and took wheels off.
Installed the 6mm spacers
Then installed the wheels again and here is results;
Checked with 90 degree level/measure and now the rears wheels are same stance as the front's
I then cleaned the Audi inside and out
I did put one of the new BBS C/F centers on one of the wheels, but I didn't like the way it sat, so will be ordering different ones.