“Finance guy couldn’t even come close....”
If the finance guy couldn’t beat your rate by 0.02 or 2.2 doesn’t matter. He couldn’t beat you bank so he just chose a number over yours to end the conversation and move on to another part of the conversation where he can make some money.
To save time you can negotiate the entire deal before arriving at the dealer. You aren’t actually saving time, you are simply using the time at home instead of doing it at the dealer.
All that said...
If you think you are going to get to the dealership and renegotiate and save even more money, you are a dickhead. If you want to shop online from the luxury of your home and get the best deal, then please, when you get to the dealership respect the salesman’s time and get it over as quickly as possible. The salesman has worked very hard to make the absolute least amount possible, please respect his time and MoveOn and give him a great online review. You may not see it but salesman work very hard behind the scenes to make your car deal happen, just because you don’t see them work hard doesn’t mean they don’t. Above all else, be nice. You may think you have a salesman that has only sold two cars in their career but you may be dealing with someone who has sold 20,000, you have bought maybe 13 cars in your life and think you’re smart. If you are nice they will work hard for you, if you are not you may pay more for a $20,000 car then you did for a $200,000 home and thank them and feel like you’ve got a great deal walking out the door.