CsvActionResult not prompting file download in View - C# MVC4

Question

I am calling a custom action from my view with a $.post and sending a couple user generated parameters with it:

$("#submitReport").click(function () {
    var carData = $("#car-select").val();
    var bikeData = $("#bike-select").val();

    if (carData && bikeData !== null) {
        $.post('/Reporting/ExportToExcel', $.param({ carData: carData, bikeData: bikeData }, true), function(data) {
        console.log(data);
    });
    }
});

Csv Action Result:

[HttpPost]
public CsvActionResult ExportToExcel(string[] carData, string[] bikeData)
{
  var dt = new DataTable();

  // Add all the stuff into the datatable

  return new CsvActionResult(dt) { FileDownloadName = "MyReport.csv" }; 
}

And the most important part, the CsvActionResult class:

public sealed class CsvActionResult : FileResult
{
    private readonly DataTable _dataTable;

    public CsvActionResult(DataTable dataTable)
        : base("text/csv")
    {
        _dataTable = dataTable;
    }

    protected override void WriteFile(HttpResponseBase response)
    {
        var outputStream = response.OutputStream;
        using (var memoryStream = new MemoryStream())
        {
            WriteDataTable(memoryStream);
            outputStream.Write(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);
        }
    }

    private void WriteDataTable(Stream stream)
    {
        var streamWriter = new StreamWriter(stream, Encoding.Default);

        WriteHeaderLine(streamWriter);
        streamWriter.WriteLine();
        WriteDataLines(streamWriter);

        streamWriter.Flush();
    }

    private void WriteHeaderLine(StreamWriter streamWriter)
    {
        foreach (DataColumn dataColumn in _dataTable.Columns)
        {
            WriteValue(streamWriter, dataColumn.ColumnName);
        }
    }

    private void WriteDataLines(StreamWriter streamWriter)
    {
        foreach (DataRow dataRow in _dataTable.Rows)
        {
            foreach (DataColumn dataColumn in _dataTable.Columns)
            {
                WriteValue(streamWriter, dataRow[dataColumn.ColumnName].ToString());
            }
            streamWriter.WriteLine();
        }
    }


    private static void WriteValue(StreamWriter writer, String value)
    {
        writer.Write("\"");
        writer.Write(value.Replace("\"", "\"\""));
        writer.Write("\",");
    }
}

When I look in the console, I can see that the data is being returned, but it doesn't prompt a file download in the browser. So I actually need to do something with the data when it is returned. I thought it would prompt a file download automatically.

Any help would be appreciated.