Ford Mustang: 2000 mustang saleen, mustang saleen, horsepower gains

Question
what would be the best exhust to put on it to add hp and make it sound great!!!

Answer
I really like bassani.  I had that on my 1998 GT.  They showed the greatest horsepower gains for my car and sounded good when i really got on it without being too obnoxious.  Flowmasters are a classic for mustangs.  You can also go the root of SLP Loudmouths or Cherry Bombs.  All depends on personal preference and if you are just talking about a cat-back or x/h pipe or headers.