Had similar along the St. Lawrence River it was shad fly season, they only come out for about 3 weeks and when you hit them its a swarm. Cleaning was as soon as you can hot water and soap and a lot of elbow grease. If you let them bake on in the sun it makes it harder to get them off. A pressure washer will take them off but be careful around decals.
After it drys use polishing compound and a buffer(be careful not to burn it with the buffer).If not confident with the buffer, just do it the old fashioned way by hand and again not on decals.
Think about things before you do them make life easier not harder.