Get some quality stuff, motorbike shops should have abundance of it. Alledgedly there are quality differences, but I have no personal experience between one brand and another,as I have only wrapped the exhaust manifolds once - a couple of months ago. i do have experience between ordinary fibreglass wraps and the "titanium" kind, though. Titanium is easier to apply, doesn't leave as much fibreglass strands all over (clothes, gloves, the engine itself - you name it...) and looks better. More expensive, though. As the exhaust on the M3W is fairly straight, you will most likely be ok with the two inch width instead of one. Quicker to apply. If you are not experienced, take your time and be accurate. Use ordinary cable ties as a temporary fixation utill you are happy, then SS ones. Tighten well using a plyer to pull while applying counterforce to the lock with the edge of a screwdriver, then fold the loose end over and cut. As for the effect on a M3W, I do not really know. The exhaust will not be as hot to touch of course, but still you will not want to touch it.... As for performance, I would be surprised if you get any noticeable effect. I wrapped the manifolds on my Roadster to reduce the under-bonnet-temperature. The engine became a little more quiet as the metallic resonance of the headers was dampened, but the exhaust note slightly deeper and more pronounced (I think..) As for performance, no effect that I know of. I am no expert on M3W, but I am not sure I would bother, unless you like the look.
