I have noticed the same thing. All Mach's have the same problem and apparently all Mustangs. it's from the use of old castings/molds for the 04 year. no sense making new molds when the 05's will be different.
I had mine replaced by the dealer and the replacemnets came in with the same discoloration line on both door panels.
__________________ 2004 DSG Mach 1 w/IUP 5 speed (Born on Date: 10/09/03)
Dyno - 1/28/04 (1300 miles)K&N Drop-in Filter, SAE - 273.8 rwhp 302.5 rwtq
Dyno - 3/6/04 (3400 miles)K&N AirCharger, SAE - 282.5 rwhp 312.6 rwtq
Dyno 4/22/05 304rwhp 326rwtq |