I've found that soaking the bugs with water first, then a good wash and dry with a good micro fiber waffle towel will remove most of them. For the stubborn ones that are left after washing, soak them with Detail Spray and rub them off with a micro fiber towel, if there are still some left, you can always clay bar them off. There are commercial bug removers available that work well too. Your local auto parts or Wal-Mart carry these products.
if you can find a castle dealer they have a product called truck and bus , i use it all the time . you spray it on let it set a few minutes and was it off with your wash mit and soapy water . they just melt off. its the best , this is a commercial product that dealers use and trucking companys use . you mix this product 50% with water and i think the smallest quanity you can buy is a gallon. good luck do a google search for a castle dealer in your area.
I use my pressure washer to spray my truck first including the undercarriage especially when there are bugs on the front of the truck before I wash. Then I use Turtlewax bug and tar remover for the dried on bugs.
bug and tar remover , come on give me a break , a bug is basicly water base tar is solvent base one product cant cut both . ive tryed that stuff when i was a kid its junk . if it works your not doing a good job , and a scrub brush on the front of my new truck what are you guys crazy . you might as well use a pot scrubber or a red 3m scuff pad . maybe a piece of 80 grit sand paper. this stuff im talking about from castle is amazing if any of you guys have a white truck and it gets fly sh$t all over it (black dots) and it dont come off with soap and water this stuff melts it.