I now always use postal money orders. If you pay with a postal money order, the postal "police" go after them for you if you do not get anything. The term anything is the kicker. If he sends you a ratty steel bumper instead of the endura, then they may say it's civil (opinion, they don't know what endura is, you paid for a bumper and got a bumper) and not do much.
If he sends you nothing, then they will almost always investigate (no offense to postal employees, but I get the impression that the postal "police" do not get to play cop to often, so they are more willing to look into these things).
You can also call the local FBI office.
Finally,
if nothing else works,
If you are mad enough,
And IF you are willing to risk retaliation (remember some things are not worth it)
bug the living hell out of him. Fill his voice mail with messages. Sign his email address up for spam emails so that his mailbox is filled with junk (try some daily scripture sites, who knows, he might convert and make it right
), Look up relatives and family members contact information and call them and explain what he did.
Just some ideas from a Dago'
Rich