Whatever you use I would put some wax back over the area after its fully clean because most cleaners will remove wax along with the bugs and/or tar. A lot of times before I was my truck(which ain't very often because it rains so G-D much) I'll spray the front end with some window cleaner (Windex) and let it sit for 15 minutes before washing it and the bugs and **** come off a whole lot easier.