It has come time for me to change the springs on my 87 E30 320i cos the ride quality is crap. I want to go the lowered suspension route and was wondering what you guys could recommend. I have seen a lot of people saying that they have 40mm suspension. I know nothing about suspension mods so could someone explain what this means aswell as tell me what to look out for.
I want the car low enough to stick to the road aswell as look cool
, but not low enough to drag the undercarrige on every small bump 
. Any help would be great.Thanks
BeemaBoy