For those of you who have installed the sparco harness bar. In the instruction, the picture for the top (b-pillar) mount shows a thick spacer between the car and the side of the bar. My bar was supplied with 4 thinner spacers instead of 2 thick ones. Should I use 4 thinner ones, or only 2? I will call sparco tomorrow but if anybody can help me out before then would be great. I just want to be sure I have enough thread engagement if I use all 4. thanks