I've taken the liberty to add a few overlays for Spirit as well. They're not perfectly placed but it's giving a good impression.
You'll see the discrepansies in the overlays when you adjust the transparency slider, seems the traverse maps could use
a slight rotation. (and don't forget to turn off Googleearth's 'Terrain' option)
Grab Spirit's kmz file here
And my apologies... this post should've been put in the 'Tech, General and Imagery' forum...