There are that many scammers out there, I wouldn't wire money to anyone. Bank transfer is much safer, but I would always pay it to the person advertising the car as at least that way you have a trail to follow if something goes wrong. Here in Oz if you put a car for sale on one of the big carsales sites you are sure to get at least four bogus buyers wanting you to send the money so the deal can go through. You want to make sure who is getting the money before you pay anything.
Just my opinion.
Regards