In your case, do not travel until you have a signed sales agreement with the dealership. Ensure that a sales manager signs off on it. Do not leave a deposit without a written and signed agreement on the price and options. You must get a manager to sign off on the deal, because some salespeople will tell you anything to get the deposit and then another salesperson will sell the vehicle before you arrive.
They can execute a buyer's agreement remotely with
VIN and sales price. Then, you shouldn't have any surprises when you arrive and speak with the sales manager who signed off on the deal. Many dealerships are honest and straightforward. Some aren't.
Also, DO NOT fill out a credit app ahead of seeing the vehicle, verifying the
VIN and finalizing price.
If they won't agree to those terms, then find another dealership. I wouldn't travel or leave a deposit for anything less. If you search dealership name you might find out if others had a positive experience.