Here is the real answer: Your contract with ANY service provider including landscaping/snowplowing needs to be as detailed as possible. Make your expectations and desires very clear, and then they will quote you based on that. Then as long as you are paying the agreed price for the agreed level of service, they will be the ones in breach of contract for not following the guidelines.

The contract should state how often or when to come plow (include a snowfall minimum usually) and what is to be done in a given visit. Then also include that salt/dirt is not to be spread to close to the vehicles so as to hit them, conceding that if you fail to move your car, that’s on you.

Again, more detail is better. Although a plow person may view that as a red flag that you will be high maintenance, and may not want to even give you a bid. But also make it clear that you are willing to listen to their thoughts/concerns/suggestions on the contract so as to allow them to do their part in a reasonable and efficient manner.

In short: communicate, and don’t be a dick.