Get the car. It may not seem as fun as a guitar, but it will open your world.
The real world is very real, and it can bite back sometimes. But, once you start earning and paying your way in this world, there is a great satisfaction in that. That sounds so dull, but it's true.
Five years from now, would you rather be graduating college with a little money in the bank and a manageable amount of student debt (or none at all), or tons of cool gear (or *lots* of great gear bought on credit) but no money to buy your interview suit?
Treat your money like your freedom. Protect it, don't waste it, respect it, and you'll always have it when you need it.
Buying and insuring your first car is the first step.
And if you already have a guitar.....