Try "Gel-gloss" for old bugs. This is a very gentle product not specifically for cars sold at Home Depot. It can be used for general pre-wax cleaning and will make your paint like glass.
If that doesn't work, try No 7 White Polishing Compound
" (not the heavy duty). This is a little more abrasive than the Gel-gloss but won't harm a clear coat if you don't grind it in. Gel-gloss can be used after No 7.
I use both of these products successfully on a regular basis, either by hand or with a buffer. They will not harm a clear coat if applied properly. If you use a buffer, practice on another car first.
For really stubborn bugs, road tar and other sticky stuff (interior/exterior) try "goo-gone" or "goof-off", both from Home Depot or your local hardward store. This is in liquid form so don't spill on anything. This is not a polishing product so just wipe it on and rub gently for awhile. You might want to try this first since you already went over the area. This is an oil based product so if you use it on your interior the residue will probably need to be cleaned. Try it on an inconspicuous spot first.
You'll need to wax after each of these products is applied. I use Blue Coral Carnuba
or McGuires wax.
Note: if the insect residue has etched the paint, you may need to use touch-up to cover it.
2004 E60 530is, Delivered 12/12/03, TiSilver/LGrey, PP, SP,PS, PDC, ACC, FRS, Step, Xenons, clear bra, body colored rear inserts. (Retired, 1983 henna red 320is)
2004 Corvette Z06 Commemorative Edition