Before this gets moved, talk to your bank about a "wire transfer". Once you make a deal on a car, have your bank wire the funds to the seller's bank. Typically, your money is placed in an escrow account and when you pay, the money is taken from there.
These types of transactions are done all the time and some banks will not charge for the service, others may charge something like $20 to $40 USD. It can take anywhere from a few minutes to an hour or so for the money to appear in the sellers bank. This procedure is probably the safest ans there is no paper involved like a check nor do you have to carry a briefcase full of $100's

like a Mafioso.
Once the seller's bank has the money, then you do the paperwork like the bill of sale, certificate of title transfer, and whatever licensing requirements are necessary.