Try using a clay bar on the affected areas, yes it can be used on chrome too. Or you can give a try at a chrome cleaner like brasso or some other good brand.
And before going on motorway or a long trip try to wax the car to protect the paint from the insects. This will create a barrier between the insects and your cars paint. If waxing the whole car isnt possible, just wax the front + side view mirrors as this is the most affected area. Plus this will also help you in cleaning your car by making it easier to remove the stuck insects.