Might try http://www.customcargrills.com/index.asp for the oil cap and the gas cap, you talking about the billet Mustang one? If so there should be a how-to for it in the How To FAQ section. Somethings not working on the Search for me at the moment.
go to signsbydrex.com
he has stuff for the grand am that fit our cars as well
if you contact him and talk to him he cam make anything you want
in billet aluminum