Rusty but fix
 

Ford did not paint the rear ends of the 05- 11. So you end up with some thing that looks like Pic 1 after the fix it looks like pic 2. Nice to have a clean but. I use Pig Spit to keep it looking clean. currently over 60K miles and still clean.

Nice, like you, of done the same to the diff on my GT.

It is always a pain to clean the under carriage, but the guys that know are impressed. When we picked up our 13 it was on a lift in the service area (as per my request). I saw a 08 gt500 on a lift for a clutch and it was disgusting how dirty and rusty it was.

So true. I know for me it drove me nuts. Could never understand why they didn't paint it!