With regards to the spring pads for the 16V, here's how it works:
There are 3 sizes for the front: 2-4
and 4 sizes for the rear: 1-4
These sizes are determined by the number of bumps, nibs, or knurls (whatever you want to call them) on the rim of the pad.
What size is already on your car depends on the length of the springs that were installed. The bumper height has to be within a certain range from the ground, and although the difference in the spring pads won't cause you to exceed that range either way, there is an "optimal" height for which the suspension was designed. The prupose of the different height pads was to compensate for any variations in the factory spring height.
The translation is that the springs and the pads are similar to a matched set. And the only way to know which pads are on your car is to look.
Hope this helps!
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