I'd say just make sure you are negotiating the OTD price.
The destination charge just about everyone pays and is typically non-negotiable.
Floorplan fee or Wholesale financial reserves, Ad fees(if any), dealer prep(if any), etc. are commonly added after one would negotiate a "selling" price... and some of them like ad fees are the cost of doing business and I think the customer should never have to cover that... Just CYA.
I personally think that $23,500 OTD (destination included) is a great price for both parties on a vanilla GT. The dealer makes about 4% profit and the buyer doesn't get bent over with crazy dealer fees.
Then on top of that you'd have about $1500 in tax at 6.5% and whatever the title and lic. fees are in your state.