generally a claybar or some solvent usually works quite well. I've detailed cars professionally for a few years in my life. What I would do if you're going to use some sort of solvent is to spray lightly in the area you need it most, wipe cleanly, use a claybar after the solvent to get any left over particles. Wax afterwards, at least in the area where you sprayed. I've also found that the more you use a better wax on the bumpers (a place that most people forget to, or don't wax) the bugs will come off quite a bit better.
I drive about 80 miles each day just to go to work, and get quite a bit of bugs on the MSP.