Webclient.Downloadstring();

var data = "{"err":[],"msg":[],"state":null," +
                  "rec":{"Vin":"1ABC2DEF3GH45678"," +
                  ""REG":"ST-ABC123","int":"12345678"," +
                  ""Make":"GMC","Model":"YUKON"," +
                  ""Type":"SUV","Color":"black metallic",";

public class Program
{
    public static void Main(string[] args)
    {


        var data = "{"err":[],"msg":[],"state":null," +
                  "rec":{"Vin":"1ABC2DEF3GH45678"," +
                  ""REG":"ST-ABC123","int":"12345678"," +
                  ""Make":"GMC","Model":"YUKON"," +
                  ""Type":"SUV","Color":"black metallic",";

        data = doc.Replace('{', ' ');
        data = doc.Replace('"', ' ');
        data = doc.Replace('}', ' ');
        var sub = data.Split(':', ',');

        for(int i = 0; i < sub.Length; i++)
        {
            sub[i] = sub[i].Trim();

            /*Console.WriteLine("{0} : {1}", i, sub[i]);
            Outputs :
            0 : err
            1 : []
            2 : msg
            3 : []
            4 : state
            5 : null
            6 : rec
            7 : Vin
            8 : 1ABC2DEF3GH45678
            9 : REG
            10 : ST-ABC123
            11 : int
            12 : 12345678
            13 : Make
            14 : GMC
            15 : Model
            16 : YUKON
            17 : Type
            18 : SUV
            19 : Color
            20 : black metallic
            21 :
            */
        }

        Vehicle vehicle = new Vehicle(sub[8], sub[10], sub[12], sub[14], sub[16], sub[18], sub[20]);
    }
}

public class Vehicle
{
    public string Vin { get; set; }
    public string Registration { get; set; }
    public string ID { get; set; }
    public string Make { get; set; }
    public string Model { get; set; }
    public string VehicleType { get; set; }
    public string Color { get; set; }
    public string Nav { get; set; }
    public string Transmission { get; set; }

    public Vehicle(string _Vin, string _Reg, string _ID, string _Make, string _Model, string _Type, string _Color)
    {
        this.Vin = _Vin;
        this.Registration = _Reg;
        this.ID = _ID;
        this.Make = _Make;
        this.Model = _Model;
        this.VehicleType = _Type;
        this.Color = _Color;
    }
}