2mm is about right. Check out this stuff from Modelers
http://www.hlj.com/cgi-perl/hljpage.cgi?MDLM1120 Its plastic, not sure it its actually styrene or not (i haven't tested that yet). I got some a short while back and have only just had the chance to use it on my ITR project. Its excellent stuff, bends real easy and holds is shape with no kninks. You do get slight creases in it as it bends but these are easily sanded out. A quality product and well worth adding to the supplies/tool box box.