How to get Data from RecordData ?

Hi,

I have a recordData used to display a simple grid.
How may I take advantage of the local!data var ?  I woud need to get the TotalCount of this RecordData for example, or to copy data in a CDT list.
Have I to cast this variable ?

  local!data: a!recordData(
    recordType: 'recordType!TT_R_Vehicles',
    filters: a!queryLogicalExpression(
      operator: "AND",
      filters: {
        a!queryFilter(
          field: 'recordType!TT_R_Vehicles.fields.model',
          operator: "=",
          value: "BMW"
        )
      },
      ignoreFiltersWithEmptyValues: true
    )
  ), 
  
  a!gridField(
    label: local!labels.units,
    labelPosition: "ABOVE",
    data: local!data,
    columns: {