sorry, what? a car, regardless of its use on the road, remains YOUR posession, in the same way as your legs are, its like telling someone they cant walk down the street with shoes on because 'its a modification to the original manufacture of your feet'.
mate of mine had a discovery 2.5tdi, he got it ecu chipped for more torque, power and as a side effect he also got an extra 5mpg out of it and less emissions. goverment tryin to tell us that is a bad thing?