Murdoc, i would be very skeptical of this transaction. The only way i would do it is if the money was put in an escrow account in which the company represents ME not the seller. In addition title would be shipped with the vehicle.
I have experience with this. I inquired about an 03 for sale on
http://www.autotrader.com with 9k miles and it was only like $19,000. The guy agreed to pay shipping if i just sent him a 30% payment to an escrow service. Well to make a long story short, the money was not going to an escrow account, but rather to his pocket(he made it look like it was goign to be escrowed with squaretrade, however square trade doesnt provide an escrow service.)
If it has anything to do with Western Union, IMO you should not do it. If you want further details just let me know.