I use 3-M bug and tar remover on my truck. Should work fine on siding I would think. You can get it at any car parts store or Walmart.
We have big bugs here, but where do you live that the bugs fly fast enough that they SPLAT when they hit your trailer anyway? Just messin with ya…
Have a Great Day!!
If it is just bug spots(spots), then TSP and bleach in water. Trisodium-Phosphate with the bleach and laundry soap will clean almost anything safely off vinyl siding with no damage, unless you use too much TSP(it is a powder)can be bought at any Lowe’s type place or a small paint shop.
If it is guts from going splat, this cleaner will work safer, but slower, than the solvent type cleaner that Kyle mentioned.
It also kills and helps prevent mold under the lapped siding.
8 years of professional painting and repainting,
Philip