@4x4inthe6 PETG melts at temperatures between 230-240C, which is 10-20C lower than ABS. That's not a lot lower, so it might be okay.
The temperature of components in the engine bay will vary a lot depending on how close to the block they are, what they do, the weather, and what sort of driving...
The infill setting only applies to the interior of the model. The air grid/grill is the exterior surface, and will still be there even with 100% infill. If you get a plastic brick back from the printing service they've screwed up in some way.
The main reason for using less that 100% infill is...
I ordered my snorkel back in April 2020. and installed it shortly after.
In August of 2020 I took it apart so I could run the axle, transfer case, and transmission breather hoses to the air box using Hauk Offroad's Breather hose extension kit. I was disappointed with what I saw.
The...