[s-cars] Suspension parts question - dimple in hood?

[Tom Mullane]

Folks,

The weekend I am swapping the H & R Sports and Bilsteins from my parts car
to my garage queen.  I one strut assembly from each car apart, and I seem to
have more parts on the stock set-up than on the modified set-up.  

I removed the assemblies from both cars and dissembled them side by side.  I
compressed the springs, and removed the nut from the top of the strut
inserts.  This allowed me to remove the whole bearing assembly and the
spring from each strut assembly.  Looking at what I have left, the lower
part of the strut assembly, I see that the stock set-up has some sort of
upside down metal "cup" still on the shaft of the insert, while there is
nothing on the Bilstein.  

Is this metal cup thingus not required with the Bilsteins?  Or is it the
thing that stops the strut insert from blowing through the rubber strut top
and into the bottom of the hood?  Looking at the FA, I think the part in
question is 4A0 412 339A.  

What's the call?  In or out?

TIA,

Tom Mullane

1995.5 S6 - Not yet road ready
1995 S6 - Parts car
1991 CQ - Injured reserve
1996 A6Q Avant - Daily driver
1999 A6Q - wife's ride