My 2 cents, as someone who has helped friends/relatives buy cars:
The next step, assuming you don’t want to pay too much, is to negotiate. I don’t know how far you’ve gone in talking to these dealers, but they may think they have you at $24.5K, they may think they can squeeze another $2.5K out of you by adding high profit extras like pinstripes, undercoating, scotchguard, etc… Don’t go for any of this stuff. If it is already on the car or they say they’ve already done the treatment, so what? you didn’t want it and you’re not paying for it.
The only thing you want out of this junk is probably floormats and possibly a cargo net/cover. Still, make them take it off at first. You’ll be trying to get them to throw them in later when the dealer thinks you’re right about to bite. Even if they say no, at the worst you’re paying for floormats you’d have to buy anyway. Make the dealer explain everything in the offer, especially anything that sounds confusing or lines with just abbreviations (Additional Dealer Profit, my eye!).
Without knowing exact details, I’d say that all you know at this point is you shouldn’t have to spend any more than $24.5K (as other posters have noted, you can ignore all the “invoice” crap, as it’s neither what the dealer actually “paid”, nor what they’re willing to sell for). How much less than $24.5K you can buy the car for depends on the local market and your negotiating skills. If one of the dealers has the exact vehicle you want sitting on the lot, I’d walk in and start dealing. Start lower than what you’re willing to spend and expect to go higher. Your opening bid should be obviously low without being insulting. Again, so much of this depends on locality and other details that I hesitate to even guess-maybe $21-22.5K.
You’ve got three dealers to choose from, so if they are inflexible, just walk. You hold all the cards. Prepare to go through the “Let me ask my manager” dog and pony show. Make sure you eat something before you go, don’t go tired, etc. Be sharp and focused. Don’t let the negotiations wander at all from the final purchase price of the car. If you have a trade or financing, etc. to talk about, this is not the time. The dealer’s job is to get you distracted in a sea of numbers, your job is to hammer them down to the lowest possible price on the car, and that’s it.
Good luck in your negotiations. Many people feel so uncomfortable in this situation that it is worth hundreds, perhaps thousands of dollars to avoid it, and this is one way car dealers make their money.