It’s a mine field and can be argued till the cows come home and that has so many loop holes solicitors love the unclear rulings, but common sense usually prevails, if it’s on the log book as a car even over 2000kg then it’s fine.
but it is handy to rember when the police say you over took them and they were doing 57 so you must of been doing over 60, “really officer your willing to state you were doing 7 miles over the limit for Your vehicle”