There are two types of vehicle import: parallel imports and grey imports. The former refers to cars that are available to buy in the UK as well as overseas, whereas grey imports are those that are obtained through channels other than the maker's official distribution system. Typically cars imported from Japan will need to have changes made to them as they often do not conform to the UK standards. For example, certain lights and internal instruments will not be allowed so will need to be modified on arrival. Similarly, most Japanese cars do not have an under-seal attached, another thing that will need to be changed before you can use it legally in the UK.