When I lived in Alaska, land of bugs galore
we used WD40, before trips
just a hose &/or a sponge after the hose, after the trips,
stuff just fell off, especially in the radiator fins
WD40 worked great on racecars too, for the burnout rubber,
especially on my 23 or 27 altered/s, smoky rolling burnouts
or the underside of the P/S tubs
where that crap builds up really bad otherwise
adds weight to the car
where the stuff got under & all over the rear of the (altered) body/turtle deck
all over the wheelie-bars etc.
good luck