Should I buy a new car, motorcycle, or save?

I took this semester off college (spring) because I hated the university I was at (D2) and I want to transfer so I decided to have a semester off just for fun and will start college again in the fall. I got a job making about 2k a month (but plan on quiting in august so about 5 months) and I have no living expenses (I'm living back at home). I will be able to pretty much save all of it. I have a 2004 mustang v6 and the tires are bald and doesn't run so good (110,000+ miles) I have also been riding motorcycles all my life and had 2 sport bikes already (ninja 250 when i was 14 and a cbr 600cc). So basically I was wanting opinions should I buy a new (new to me) car, a motorcycle, or just save it. I don't have to pay for anything in college as far a tuition and books. I will be pledging a fraternity so I thought it would be smart to save the money for that because I know that they take trips and everyone in them generally has money to blow and have fun. I will have a little over 10k hopefully and my car car sale for about 4k, So what are your thoughts?? Sorry for the long explanation that might not make sense, I just wanted everyone to have a good idea of my situation