If a person forgot to switch off his car lights before Shabbat, may he ask a gentile to turn off the lights?
Rav Shemuel Pinchasi ruled that the Halacha in such a case depends on the potential consequences of leaving the lights turned on throughout Shabbat. If the lights would drain the battery completely and cause the person considerable inconvenience, such as by having it towed to a garage, then he may ask a gentile to switch off the lights to spare him this inconvenience. If, however, leaving the lights on would only weaken the battery, but not drain it completely, such that no particular inconvenience would result, then one should not ask a gentile to switch off the lights.
If it snowed during Shabbat, may one ask a gentile to shovel the snow in front of his home?
Rav Pinchasi ruled that one may ask a gentile to remove the snow from in front of his home on Shabbat, due to (among other reasons) the potential danger the presence of snow and ice causes to pedestrians. There is even greater room for leniency, he adds, in locales where fines are imposed upon homeowners who do not remove the snow from the sidewalk near their homes. Preferably, however, one should ask the gentile not to throw the snow a distance of four Amot (6-8 feet) at any one time; he should instead try to move each shovel-full of snow a shorter distance away from the sidewalk.
This is the position taken as well in the work "Mishneh Halachot" (vol. 4, chapter 45).
Summary: If a person forgot to switch off his car lights before Shabbat, and leaving the lights on throughout Shabbat would cause him considerable inconvenience, he may ask a gentile to switch off the lights. If snow fell on Shabbat, it is permissible to ask a gentile to remove the snow from the sidewalk in front of one's home.