JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.highcharts.com/highcharts.js"></script>
<script src="https://code.highcharts.com/modules/exporting.js"></script>

<div id="container" style="min-width: 310px; height: 400px; margin: 0 auto"></div>

JavaScript

var dataArray = [{
  ErrorDate: "2017-09-07",
  Brand: "Toyota",
  Count: 3
}, {
  ErrorDate: "2017-09-02",
  Brand: "Ford",
  Count: 258
}, {
  ErrorDate: "2017-09-03",
  Brand: "Ford",
  Count: 239
}, {
  ErrorDate: "2017-09-04",
  Brand: "Ford",
  Count: 197
}, {
  ErrorDate: "2017-09-05",
  Brand: "Ford",
  Count: 187
}, {
  ErrorDate: "2017-09-06",
  Brand: "Ford",
  Count: 418
}, {
  ErrorDate: "2017-09-07",
  Brand: "Ford",
  Count: 344
}, {
  ErrorDate: "2017-09-03",
  Brand: "Mercedes",
  Count: 43
}, {
  ErrorDate: "2017-09-04",
  Brand: "Mercedes",
  Count: 220
}, {
  ErrorDate: "2017-09-03",
  Brand: "Chrysler",
  Count: 3
}, {
  ErrorDate: "2017-09-04",
  Brand: "Chrysler",
  Count: 3
}, {
  ErrorDate: "2017-09-06",
  Brand: "Chrysler",
  Count: 6
}, {
  ErrorDate: "2017-09-07",
  Brand: "Chrysler",
  Count: 1
}];

var chart = Highcharts.chart('container', {
  chart: {
    type: 'spline'
  },
  title: {
    text: 'Car Metrix Test'
  },
  subtitle: {
    text: 'Irregular time data in Highcharts JS'
  },
  xAxis: {
    type: 'datetime',
    dateTimeLabelFormats: { // don't display the dummy year
      month: '%e. %b',
      year: '%b'
    },
    title: {
      text: 'Date'
    }
  },
  yAxis: {
    title: {
      text: 'Count'
    },
    min: 0
  },
  tooltip: {
    headerFormat: '<b>{series.name}</b><br>'
  },

  plotOptions: {
    spline: {
      marker: {
        enabled: true
      },
      pointInterval: 24 * 3600 * 1000
    }
  },

  series: []
});


var seriesArr = [];
dataArray.forEach(function(point) {

  var newPoint = [point.ErrorDate, point.Count],
    seriesIndex = seriesArr.findIndex((series) => series.name === point.Brand);

  if (seriesIndex === -1) {
    seriesArr.push({
      name: point.Brand,
      data: [newPoint]
    });
  } else {
    seriesArr[seriesIndex].data.push(newPoint);
  }
});

seriesArr.forEach(function(series) {
	chart.addSeries(series);
});