Mystican... I've heard (but haven't yet tried) that WD-40 works.
As an aside, I was driving from Nice to Heidelberg last year, and around Genoa stopped for gas. The windshield was black with gnats and bugs. The guy grabbed a spray bottle of liquid spray soap based on what they call "Marseille soap" here in Europe. I've never seen anything like it, they washed right off, almost completely, after a few squirts of that stuff. Wish I knew what it was in the U.S.
Have you tried Simple Green or some of the commercial bug removers?
Up here in PA there are plenty of farms, so the bugs are even worse if you smell fresh "fertilizer." My advice is (in order of importance):
(1) Keep your car washed frequently / never put it away really dirty. This facilitates #2.
(2) Clean bugs off with quick detailer immediately after each drive. Yes, this gets old but it's much easier than letting them dry on the paint. Keep a stash of microfiber towels (preferably white) for this purpose. I hit the nose, then mirrors, A-pillars, & side intakes.
(3) Avoid driving at night.
(4) Slow down when driving near farmland. Below 45mph preferably. When I get my right foot into it and exceed 70 or so the bugs remind me of the Millenium Falcon at warp speed.