My thought re. driving on Lantau is that you can't drive around South Lantau without a permit (Lantau Closed Road Permit (LCRP), which is for private cars only, has to be applied for, and for which the driver must hold a valid full Hong Kong driving licence). North Lantau, because of the airport, cable car, and MTR has decent public transport so a car isn't really necessary. South Lantau doesn't have good public transport, roads are congested and not "great", so a car might be necessary there but you aren't going to get a permit to drive there.
And it's "Chek".
