StangMods is now proud to be an authorized SLP Performance Parts dealer. SLP makes a variety of exhaust and performance products for the late model Ford Mustang. Their hallmark system is the Loudmouth cat back which produces a loud and intoxicating exhaust note. The Loudmouth II system is slightly quieter but still gives you that authentic, SLP Mustang sound. Enjoy free shipping and the lowest possible pricing on all SLP Mustang parts.