About 2 years ago, I did the undercarriage of a 12,000 mile gnx. The car was stored in a damp garage,undercarriage was a mess. I removed the rear end assy. glass bead the rear cover, soaked the housing with rust-mort, cleaned,wire wheel the entire housing, I applied ppg dp90 black epoxy primer, and painted with semi-gloss black. Note, I removed brake lines,and items.. I have some photos, i can e-mail to you.. Best wishes with job!!!