When we take a car to the 'start' we just leave it there in a real parking space (that is, not parked illegally),
or if that's not an option we've even left it at the side of a mountain (off the road) in the Pyrenees, with a note saying we'd be back in a month.

Generally we tend to not overthink the risks, mostly (like 99.9% of the time) everything is OK.
And I feel the .1% of the time that there actually IS a problem won't be easily (or at all) lowered.