Always nice to have an excuse to drive the Lotus!
Since you've already gotten your struts installed, this won't help you but I didn't use the side pieces. I mistakenly thought that drilling into the curved fiberglass under the rain gutter would be a problem, So rather than use the fabricated pieces that came with the kit, I took a 1" square aluminum tubing. I cut a half round "fish mouth" at one end to catch the strut that goes across the car under the rear window. I had to carve up the back a little to get around the seat belt strut connection and bolted that to the wheel well. but otherwise it was pretty simple and is very sturdy.
I'll bet your really happy with your struts. It's one of the best things I've put on my car!