The stock R/T strips are inline with the door handle.
http://image.motortrend.com/f/auto-shows/details-drop-on-dodge-challenger-r-t-classic-starts-at-34-005/14276210+w750/2009-dodge-challenger-r-t-classic.jpg
Other ones are lower, so technically you're not "wrong"
http://www.ridergraphix.com/Challenger_70RT_Blue1.jpg
http://www.performancecargraphics.com/images/Stripes_Lettering/Challenger/70_Mid_RT_SE.jpg
http://assets.hemmings.com/story_image/144561-500-0.jpg?rev=4
If I had a choice I would have done it down the R/T-style path, but I personally don't like any stripes at all, so whatever. If you like it, cool.