Sealed efficiently and consistently all metals and plastics in the engine compartment. Thorough washing the engine, however, is strongly recommended prior to use, unless you want to preserve the dirt. Rust and unwanted leakage currents are suppressed and the way everything shines very nice and gives a good impression. I had occasional teething problems in wet weather. Silk I have the entire engine electrics and electronics injection fogged so is peace. I would highly recommend this product. Did I just bought a second box to spray a few subtleties to.
Conclusion: The product makes sense and is just clearly recommended for older vehicles.