ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ObjectOutputStream out = null;
        try {
            out = new ObjectOutputStream(baos);
        } catch (IOException e) {
            e.printStackTrace();
        }
        for (Car element : carList) {
            try {
                out.writeObject(element);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        byte[] xaValue = baos.toByteArray();


deserializacja

byte[] bytes = theInteraction.getValue(i);
                ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
                ObjectInputStream in = new ObjectInputStream(bais);
                while (in.available() > 0) {
                    Car element = (Car)in.readObject();
                    this.value.add(element);