Go to Ebay and search for Buick rotors & CAI, or just "Buick PA & LeSabre parts".
Here you go, I'll make it easy for you!
http://search.ebay.com/Buick-lesabre...ageNameZRC0022
eBay - Buick lesabre air intake, Parts Accessories, eBay Motors items on eBay.com
http://search.ebay.com/Buick-slotted...ageNameZRC0024
eBay - Buick slotted rotors, Parts Accessories, eBay Motors items on eBay.com