Here is the progress of modding your first Mustang or first exhaust system.
1. Buy flowmasters
2. Realize how much better everyone else's car sounds then yours.
3. Buy ( any other exhaust system name here ) and marvel at how much better it sounds then your flowmasters
4. Crap on flowmasters for the rest of the time your on the forums.
My first exhaust system I modded was flowmasters, it was also the last time I bought that system again. They just sound so raspy and hollow. Ever notice how hollow a house sounds before you move into it when there is nothing in there for furniture or anything else? Thats kinda how I feel about flowmasters