I have an R1150RT which is titled as a 2004, has the twin spark ignition, etc. and looks like any other 2004. I never gave it another thought... Until I parked next to another Piedmont red 2004 R1150RT this morning and discovered that they are noticeably different colors. This took me to a curiousity search about the color and ultimately to the VIN. Turns out the color code on my bike is actually Sienna Red (Red 3) whch is an '03 color. The VIN also defines the build date as May 2003.... But, of course, it has the '04 Twin Spark engine. My biggest question other than figuring this bike was probably part of a transitional production run is, what problems might I run into while ordering parts? So far, anything I've purchased from an '04 fiche fits. Are there any known differences?