looking up the cables in ebay i noticed two kinds of descriptions: first kind (usually having a white cable) specifies that it has original FTDI chip but does not specifically say that its compatible with ISO9141 protocol. The other kind (usually with blue cable) does not mention anything about original FTDI chip, but says that its compatible with ISO9141 protocol. Protocol support is necessary for Alfadiag to communicate with ECU and ftdi chip ensures more reliable usb-->com port emulation than a generic chip and also vista drivers availability. Vista download automatically FTDI latest drivers. These do not mean that first or second kind of cable don't work, but i would feel better with both specs indicated before i buy a cable. The interface in the first link indicates both! So i guess its a good combo, more preferred than an ebay item.