I have been reading some threads on diesel performance chips on this site and other sites but no real recent ones. Has anyone recently fitted a chip to a 2006 E53 diesel .ie what brand have you used and what were/are your thoughts on it.Was it worth the money,there are many cheap units available starting at about $150 along with some more expensive units going up to about $1500. Even though the vehicle has good power standard a little bit more never goes astray.We do quite a bit of towing with our vehicle as well. Thanks .