Ignore the reporting requirement. Banks are required to report large transactions but that has nothing to do with taxes, there is no special reason the IRS will or won't look at you over this. If it is more convenient for the money to go directly to the dealer, do that. If it is more convenient for the money to come to you, do that instead. Form 3520 is not required unless you receive a gift of more than $100,000 from a family member or more than $19,570 from a foreign trust or corporation.
In short, just do whatever is best for buying the car, don't worry about the bank notification rules, and don't play games.
