I scratch thick, yellow bug guts off my bumper all the time..
 

With my fingernail.

That is all.........

I use windex.

Soak it wait a minute or two, bugs wipe right off. Does remove wax on my cars since I never wax them.

I use spray detailer and lightly wipe it off with a microfiber. I obsess over my paint.

Try finishkare 425 after washing/waxing. After your drive they'll rinse right off with a high pressure stream.
If you wait too long the juice dries up. Lots of protein in those bugs, goes well with dark chocolate with at least 72% cacao. Sweet and salty. Obviously vegans will not agree.

I keep it waxed so they just pop right off.

http://i868.photobucket.com/albums/a...psuvyldchu.jpg

Old biker trick to remove bugs from a windshield............Get a clean,old t-shirt or towel and soak it in warm water. Then just lay it on the bumper for several minutes and the bugs will just melt right off.........