A trick I've learned from my professional auto/motorcycle detailing buddies is to wet down what your working on, then apply Tuff Stuff fabric/vinyl/carpet cleaner to the bug affected area. Let sit for a couple minutes, but not until dry, and then wash the vehicle using your favorite product. Virtually no scrubbing and everything pretty much wipes right off. You can get Tuff Stuff at most retailers including Walmart, Auto Parts stores, etc. Super gentle foam that works fantastic. It's also great used on leather seats, at least the tan ones in my Lincoln Towncar. It even makes the stitching come out looking brand new.