I'm a little confused about Volk's TE37. From the Tirerack, Volk's TE37 is available in silver and gunmetal. However, from other vendors, Volk's TE37 specifically for Porsche is only available in bronze colour. Another thing is that the TE37 from Tirerack does not have the sticker that says "Rays Engineering" and "Volk Racing", but others do. Are they all TE37 ? Any difference in terms of make (country of origin) and weight ?