I used Unichip in my E60 M54 engine with a significant gain (+30 BHP from dyno) It last for 2 years and need to remove (engine can't start)
The ideal tuning should be OBD2 flash which is completely reversible. I found a device call
"BlueFin" but the have only for turbodiesel engine
Anyone knows about OBD2 flash tuning for non turbo engine please help