Local or other Junkyards ( you can find them online!)
Ebay or similar auction site
Companies like Inline4
Use a search engine like Yahoo,
http://search.yahoo.com/bin/search?p=junk+yards
http://www.japantrading.co.jp/yards.html
http://search.yahoo.com/search?p=salvage+yards
http://www.junkyarddog.com/
Take a gander at a few of the links and see what you can find.
Good luck,
A.