It's pretty simple, they need to make money and I assume you want to save money. Hopefully, both sides can meet in the middle and make a mutually beneficial deal :E
Personally, I tell the salesperson up front (first contact) that I will only accept a 'skinny' deal. I know my bottom line (purchase/trade/financing) before I even step foot on the lot. They (sales person) can keep going back to their sales manager as much as they want to 'approve' the deal. However, if this tactic happens more than once, they will find an empty chair as I walk out the door and off the lot. :R:W:E
Don't let emotions affect your deal.:S
Good luck!