When I make my mind up on what I want,
This is your problem right here. Car salesmen car smell indecision a mile away. Unless they sense you're committed, they just see you as fishing for prices. They're not going to give you their best price unless you're willing to sign a contract right then and there.
Come up with a list of what you want and price you want to pay for it, then just go in and tell them and be ready to sign. If they can't or don't want to do the deal they will just tell you.
^The above is spot on. If you've done your research you should #1 Know how much you should be paying and #2 Know how much you're happy to pay. When you've actually made a decision, go into a dealer, hand over your credit card and tell them they can take a $500 deposit right now if they can give you xxxxx for $xxxxx. If they can they will (might be a little back and forth). If your offer is reasonable you shouldn't have a problem getting the deal. If not, walk away - if they don't chase you or call you back within the next hr, they can't make the deal. Then go to another dealer.
Via email I got a sense of the dealerships I was happy to work with. However the real price came to fruition when I was physically in the dealership ready to sign.
Side note - Dealer called this morning. My car is expected to arrive Tuesday. So hopefully with some luck I'll be in a position to pick up Thursday/Friday this week.