"If it's taxable, it's negotiable". The $299 Consumer Advance Plus should be removed.
Vehicle Inventory Tax is nonsense - just them adding a few bucks to help them pay their floorplan costs. Tell them to knock it off or you will go down the road to a seedy Renault dealer and buy one of their insipid vomit comets - like a Sentra or worse - a Kicks - for way under MSRP. Very few cars sell at MSRP anymore.
For $265 worth of non-tax line items, most of which are inspection, registration, title, etc - all necessary - and the doc fee, which pays the salary of the woman in the billing office who types 1.960 words a minute (you should hear them type - sounds like a woodpecker on crack), just pay it and buy the car.
What I'd want to know is whether their stated "Market Value Selling Price" is actually MSRP. I am assuming it is because 23500-24000 is the current range for an SEL.
In your shoes, I'd go for the throat and offer $300 under sticker - which effectively eats the non-tax line items - with that Consumer thingie removed, and then make sure they apply the $500 rebate if financing through HMFC. That 500 and the 300 whack the price down to $23k plus the silly town/county/state costs.
You don't usually get your best deal until you've said "no" at least three times. It doesn't hurt to negotiate. Tell them you're ready to buy, but will only sign at the right price. Remind them that if you get up and leave, it will be the last time they ever see your silky smooth bootie as it wiggles out the door - NEVER to return. If you are approved for financing and ready to buy, they will do everything they can to keep you from walking. Be polite but firm. You are ready to buy but at the price you feel is fair.
Worst case - in any car deal - is that you pay "too much". Happens to hundreds of people a day. It's a survivable incident. That's worth repeating here because people get ulcers and infarctions getting all twisted up over trying to "get the best price" and it takes ten years off their life. Although buying a car is not a fun process, approach it with the necessary information and a smile and do your best to get a killer deal. The sales guy/gal has a singular focus on selling you a car no matter what the numbers look like. If you don't buy, they don't earn anything. The manager's job is to clean out as much of your bank account as possible so the dealer can make a profit. Your job is to spend as little as possible and buy the car at a fair price. Never get mad at the sales rep - they're not making up the numbers. It's the sloppy bookie-lookin guy at the desk that you're really working with. Politely say "no" until they get to the figure you are willing to agree to. Then remember to say "no" to everything when you're in the box, unless there is something you actually want, such as the Electron Insurance for the nitrogen they put in the tires.
Good luck and keep us posted. Always fun to celebrate successes when a new/repeat Elantra owner joins the club.