JSFiddle - React, Tailwind, and code Playground

HTML

<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=true&language=en&region=GB"></script>
<div id="map" style="height: 400px;"></div>

JavaScript

var map;
var zoomLimit = 6;
var dealer_markers = [{
    sales: '1',
    aftersales: '0',
    name: 'Bob One',
    lat: '51.595212',
    lng: '-2.400068',
    adr: 'Some Address',
    pc: 'In Some Place',
    tel: '21312312312',
    url: '.',
    avr: '',
    position: '1'
},
{
    sales: '0',
    aftersales: '1',
    name: 'Bob Two',
    lat: '52.306323',
    lng: '0.000778',
    adr: 'Some Address',
    pc: 'Some Place',
    tel: '213213123123',
    url: '.',
    avr: '',
    position: '2'
},
{
    sales: '1',
    aftersales: '1',
    name: 'Bob Three',
    lat: '51.742384',
    lng: '-0.488795',
    adr: 'Another address',
    pc: 'More place',
    tel: '23423423423',
    url: '',
    avr: '',
    position: '3'
}];

function _newGoogleMapsMarker(param) {
    var r = new google.maps.Marker({
        map: param._map,
        position: new google.maps.LatLng(param._lat, param._lng),
        title: param._head,
        icon: "http://downloadicons.net/sites/default/files/map-marker-icons-2254.png",
        originalicon: "http://downloadicons.net/sites/default/files/map-marker-icons-2254.png",
        hovericon: "http://icons.iconarchive.com/icons/paomedia/small-n-flat/24/map-marker-icon.png"
    });
    if (param._data) {
        google.maps.event.addListener(r, 'click', function() {
            // this -> the marker on which the onclick event is being attached
            if (!this.getMap()._infoWindow) {
                this.getMap()._infoWindow = new google.maps.InfoWindow();
            }
            this.getMap()._infoWindow.close();
            this.getMap()._infoWindow.setContent(param._data);
            this.getMap()._infoWindow.open(this.getMap(), this);
        });
        google.maps.event.addListener(r, 'mouseover', function() {
        	this.setIcon(this.hovericon);
        });
        google.maps.event.addListener(r, 'mouseout', function() {
        	this.setIcon(this.originalicon);
        });
    }
    return r;
}

function init() {
    var mO = {
 ...