So the stock Mustang isn't enough for your altered ego. You have spent a lot of money for your vehicle and it isn't all that you want it to be. There still is hope to have the meanest Mustang on the road. Whether you went with the V6 or the V8 you can still add to your performance. Mustang performance parts come in all shapes and sizes as well as a variety of price ranges. Spending more money doesn't necessarily mean more power or performance. Generally the more you spend the more you gain but this isn't true in all cases.
There are many parts that will improve your Mustang's Performance dramatically and not break the bank. The place to start for most people is with something easy like an air intake rather than with something a little more complicated like a turbo. Intakes will generally be cost effective and very easy to install. With a couple of tools and about 30 minutes you'll be able to optimize the airflow into the engine. Airflow to your engine is important when it comes to more power, adding airflow to your engine increases torque and horsepower, as well as fuel economy believe it or not.
Another Mustang Performance Part that will add to the muscle car feel is an Exhaust system. Installing an exhaust system will increase your flow of exhaust out of your engine, which helps it perform more efficiently and with more power capacity. It makes it so the engine has to do less pushing to get the exhaust out, which frees up some power. It also comes with the priceless sound of muscle. Installing an exhaust system for your mustang is a little more complicated than the intakes. It will take a little more time and a few more tools. If you aren't an experienced mechanic it is probably best to have one install it for you.
Finally there are the Mustang Performance Chips that only take about ten minutes to install. Mustang Performance Chips can be installed by anyone. The chip reprograms your Mustang's inner computer to run more efficiently. That means more power, and better fuel economy, which is great for the weekend warrior type. Great fuel economy for commuting to work, and more power for the weekends at the drag strip... or the guy next to you at the light.