I would say invest in the car. More importantly invest in getting your license and saving up to be able to afford insurance, basic maintenance and gas, etc. A car is an important purchase in order to get better jobs, become independent, and to pull sick off road trips whenever you want.
Shoes can be easily bought as a gift by someone else. Plus winter is coming up soon so you might be wearing boots instead of your nice shoes/sneakers/whatever you're planning.
Guitar or a phone can easily be made into a birthday gift if your parents would be able to do that. The purchases are more frivolous but can be turned into something other people can get for you.
The youth trip is definitely worth investing in since it's an good experience without a price tag.
It's really tempting to spend money when you have a bunch saved up, but this is great practice for when you're independent. You need as much money saved up for the worst case scenario or for the next big important life purchase like a home or an apartment. Imagine if you were currently living on your own without your parents and calculate how much you'd be spending on food and daily rent. It'd be taking up a lot of your savings and with your current job, could easily be unlivable (I actually don't know how much it costs for basic rent in St. Louis but you wouldn't survive here where I live on 440 a month).
