Latest experimental - I’m using the launcher - grabbed every update over the last week.
I have just tried moving the engine - 1 tile forward, this time it is past the row of windshields, and on the front/outer frame of the van. Sound meter halved to constant seven, but I just took a small turn at 70km/hr - sound dipped to 3, but got deafened still - ears ringing momentarily first this time.
The van is in mostly good nick - but not anywhere near fully repaired, but that never mattered for this design before.
Edit: Tried a few more locations for the engine - cant get lower than 7 Sound. The descriptor for the engine noise on screen is the usual “whirr” and “humm” etc. There’s no on screen text message for a backfire?
Can recreate it every time now going pedal to the metal on a long straight happens quite quickly, and not necessarily at top end speeds - always been over 60km/hr so far.
Edit 2: Apologies - it’s the diesel 4 liter engine, not gas. Cheated in a few different engines to test - similar results.