Yes you have to take off the door panels. There's an article floating around that shows you exactly how to do it. I couldn't find it but maybe someone else can post it up.

Vinny 2000 T-RED CSVT MODS: 18" REV model 2 ST200 struts/Roush springs CTA intake Pipe/K&N Filter Dtec Heatshield Optimized TB True Duals w/ magnaflow mufflers/resonators