Is there anyway to make my car sound more like a sports car without burning a whole lot of cash

 

get a magnaflow muffler and bolt it onto the stock pipes
that'll give you the most bang for your buck but will give you ZERO performance increase and is always more likely to decrease your performance. (however unlikely)

 

With my Nissan maxima I just ordered a muffler of my choice off flea bay. Had a local exhaust shop Fab me up a 3'' cat back 180.00 not including the price of muffler. That would be your best bet OP