Tune works with 135i/335i/535i models and can be VIN unlocked for free (you load the latest N54 firmware, which will clear the VIN lock - do not start the engine, then reload the N55 firmware - just beware that it will relock to the car if the engine is started - it is best to do this in the new car it is installed in, as it will then relock to the correct VIN).
This unit can also be used on N54 models by purchasing the matching harness and updating the firmware as required.
The installation is quite easy and the unit is invisible to BMW service equipment.
I'm selling only because I am going back to stock for sale.
Local Vishnu Australian support is available.
More info at
http://www.procedetuning.com
Cost over US$800 but happy with AU$250 plus postage.
PM if interested.