customizing jqGrid search

Grid version 4.4.4 on my asp.net web form in vb. I able to load the data on my project and use the search on the toolbar of the jqgrid table. Is there a way to customize the search of it i want with only option to search by Car_No only and contains.

enter image description here

Here's my code on the grid

 function loadAuditLogs(Auditlog) {

            var lastsel;
            var startpage = 1;
            $('#Auditgrid').jqGrid({
                datatype: 'local',
                data: Auditlog,
                editurl: 'clientArray',
                colNames: ['CAR_NO', 'DEPTID', 'BFGSECTION', 'AREAID', 'AUDItdATE', 'ISSUEDTO', 'ISSUEDDATE', 'CURRENT_APPROVER'],

                colModel: [
                         { name: 'CAR_NO', index: 'CAR_NO', editable: 'true', align: 'center', width: '170', resizable: false },
                         { name: 'DEPTID', index: 'DEPTID', editable: 'true', align: 'center', width: '50', resizable: false },
                          { name: 'BFGSECTION', index: 'BFGSECTION', editable: 'true', align: 'center', width: '175', resizable: false },
                           { name: 'AREAID', index: 'AREAID', editable: 'true', align: 'center', width: '200', resizable: false },
                            { name: 'AUDItdATE', index: 'AUDItdATE', editable: 'true', align: 'center', width: '100', resizable: false },
                             { name: 'ISSUEDTO', index: 'ISSUEDTO', editable: 'true', align: 'center', width: '175', resizable: false },
                              { name: 'ISSUEDDATE', index: 'ISSUEDDATE', editable: 'true', align: 'center', width: '100', resizable: false },
                               { name: 'CURRENT_APPROVER', index: 'CURRENT_APPROVER', editable: 'true', align: 'center', width: '175', resizable: false },



                ],
                pager: '#Auditgridpager',
                viewrecords: true,
                forceFit: true,
                shrinkToFit: false,
                width: '1150',
                emptyrecords: "No Record/s found",
                loadtext: "Loading",
                rowList: [5, 10, 20, 50],
                height: 'auto',
                caption: 'Audit Logs',
                onCellSelect: function (rowid) {
                    window.location.href = "http://stackoverflow.com";
                    var gridId = $.jgrid.jqID(this.id);
                    if ($(this).jqGrid('getCell', rowid, 'shield') === '1') {

                    } 

                }


            });

            $('#Auditgrid').jqGrid('navGrid', '#Auditgridpager', {
                edit: false,
                save: false,
                add: false,
                cancel: false,
                del: false,
                search: true,
                refresh: true
            });


        }

Sorry for my bad english hope you understand what i mean.