The other small detail that really bugged me when I got my S2000, was the way that the mirror coating on my rearview mirror had delaminates. It was a cosmetic annoyance, but I saw it every time I looked into the mirror. So I ordered a used replacement, and finally got around to installing it.
Here you can see the edges of the mirror look like crap.
There is a small screw on the underside of the mount to the mirror. Turn that screw counter-clockwise to loosen the spring and slip out the old mirror.
New mirror v the old mirror
When I went to install the new mirror, I found that the screw was terribly stripped making it impossible to torque down the screw/spring to fasten the new mirror properly. So I also swapped in the hardware from my original mirror.
With the new hardware in, the mirror fastened up easily to the windshield and is solidly attached. No more gross mirror to look at!
Took about 10 minutes.