Final answer:
It is likely illegal to carry an open alcoholic beverage in a parking lot due to open container laws and potential golf course regulations.
Step-by-step explanation:
Whether a golfer can carry an open alcoholic beverage in a parking lot to retrieve an item from their car depends on the laws and regulations of the specific jurisdiction and the policies of the golf course in question. Most places have open container laws that prohibit the consumption of open alcohol in public areas such as parking lots. Additionally, many golf courses have their own rules about where alcohol can be consumed on their premises. It is crucial to be aware of these regulations to avoid legal issues.