does high level input reduce engine noise

When working with a 4 ch. amplifier, they usually have both high-level and low-level inputs. 

Low-level output voltage is between 2-4 volts, which is relatively weak and succeptable to corruption.  I understand that keeping power cables and Low-level RCA cables far away from each other will reduce engine noise.  Sometimes it is not physically possible, so would using high-level inputs be a better solution for these applications?

All things being equal, Are using High-level inputs better at rejecting engine noise?

Not if the noise is injected BEFORE the previous output circuit.

It should be if injected between the output circuit and its connectors and the next input circuit - unless it is of higher impedance which may make it more sensitive.

Not that I know how those interfaces are arranged in reality.