Ripples and other normal errors

[Godo]

Hello - as you can see below I have some strange errors in my bake. This causes the rear, shaded area to look gouged out when rendered. There's also a strange area of discoloration, I have no idea what that is. Do I need more polys on the wheel? I think I have enough, but I dunno... I'm following along poop's tutorial, and I got as close as possible with the cage, but I'm still getting those ripples.

Normal map
http://img.photobucket.com/albums/v655/godo/M5A1%20Stuart/bogeylo_wheelnormalsmap_Err.jpg

Render
http://img.photobucket.com/albums/v655/godo/M5A1%20Stuart/stuart_normalErr1.jpg

High-Low Comparison
http://img.photobucket.com/albums/v655/godo/M5A1%20Stuart/hi-lo_comparison.jpg

[Kickflipkid687]

Thats probably because your low poly was too far from the highpoly and the raycasts or w/e missed during the normal projection. This effect happens if you have the cage too far from the low poly. So you might need more polies, or could tweak the cage, or just manually fix it in photoshop.