Probably no extra multi storey car parks in centre as there will be major changes soon when terminal changes are confirmed and there is no point in putting one up to be pulled down again also T1 car park will need to come down anyway.
There is a major car park under 23R approach nearly finished (9000 cars) and a multi storey in Airport City to be built. Some of the stands have been handed back for aircraft parking this winter.
We had this argument last winter about diversions and it has been made clear it upto the handling companies to tell the airport what they can
or will handle so before that is confirmed there is no point in saying yes
unless it is an emergency for what ever reason.