Where did he move to? Does he use it on the road or track? One of the cars that the police in Adelaide were giving a defect sticker to when it left the car show was a newer M3 BMW which the owner had spent a lot on modifying. I spoke to him at the show and he did say to me " I hope i dont get stopped on my way out" People there know you cant modify your standard car without the risk of getting pulled. Unlike here there is no yearly MOT tests in South Australia so you can take a chance if you want to.
Maybe if you are emigrating you can take a car with loads of modifications but I think you would still run into problems.