I have stumbled upon a great product that will wipe the bugs and tar right off your vehicles. Its called "Little Effort". Mix it in a spray bottle with tap water and spray the bug guts on your vehicle, wait about 5 seconds and the guts wipe off like you had just hit them with boiling lava. This stuff is great!!! I think you have to order it to get it....my wife bought a whole case of the stuff.
Edit : www.littleeffort.com
or you can call them via their phone number which is 1-800-259-6909. Sorry bout that but I thought I put a link up when I posted this.