Selling for $15 + shipping, this will fit your serpentine belt tensioner. Brand-new, never used, I accidentally ordered two of them assuming it was going to fit on my AC belt tensioner. Sells for $20 + shipping on ECSTuning, so you can save a couple bucks. The brand is INA, which is the OEM, so it is factory-quality.
http://www.ecstuning.com/BMW-E46-330...lts/ES2137092/
