My Mustang is a 2005 Stage 1 Roush edition with about 16,000 miles. Some off the upgrades include;
Exterior
ROUSH 6 Piece Aerobody Kit , ROUSH 18-Inch Chrome Wheel & with High Performance Tires, but I changed the Roush exhaust for Flowmaster Exhaust and gave it a better sound and performance about 10 more HP, also added some off road X-Pipes added about another 10 HP,  ROUSH Exhaust Tips , Lower Valance Fog Lamps…
Interior
ROUSH Sport Leather Seating, ROUSH White Face Gauge Cluster w/ Illuminated "Jack Roush" Autograph, Interior Dash Trim Kit, Billet Aluminum Shift Knob w/ Grips, Door Sill Plates….
Engine
SCT SF3 / XCal3 Power Flash Mustang Tuner adds about 22 HP, SHAKER Ram Air/Cold Air Package adds about 25 HP