I can't think of one reason why you would want to leave them out. If you have them, just install it. It's there to protect the strut, not to look pretty.
Tony
1998 SVT Contour (B/MB) #542 3L
1998 SVT Contour (SF/MB) #1266 parts car
2000 SVT Contour (SF/MB) #1533 3L swap to begin!
