HI mate, I got the chip on ebay from a seller in the US. I'm very happy with the results and would recommend it, but you will need to get it dyno tuned by someone with the time and knowledge to adjust accordingly. I paid $180 for the chip. $68 for postage (international express postage) and got stung $300 for the upgrade (ripped off). Total excluding installation and setup $548 compared to $1100 approximately for new unit. I missed on a couple of earlier chips in Australia for $400 so that seems to be the going rate there abouts second hand. If you looking for one you need a H series chip for the 4.5L and an initial map and software can be downloaded free of charge from chip torque. I was unlucky with the update as the BMW chip was unique so stick to a standard H series and it go straight in. If your not sure whether its correct or not call chip torque and quote the code and they'll tell you whether it okay or not.

Good luck.