The Sportline kit also comes with guides how to trim the bumpstops in the front. Which bumpstops? cause from pictures of an install of the springs, it looks like they are trimming those rubber things ontop of the strut. And do I still use those rubber things with my caster/camber plates?

 

The rubber bumpstops are simply to prevent the strut from bottoming out. Cutting them just helps give a bit more room after lowering the car.

With most aftermarket struts that bumpstop can be tossed... with the stock struts I would trim it...

Sincerely,