Here are the most likely explanations:
🚗 1. Accidental contact in parking areas (most common)
A plastic bottle could get caught in the wheel well if she:
parks near litter or trash
drives over a bottle without noticing
It may just be getting lodged temporarily and only noticed after parking again
🅿️ 2. Someone placing it deliberately (possible but usually harmless)
Sometimes people:
put objects on cars as a joke
or as a warning marker in crowded parking lots
This is usually not dangerous, but still worth understanding the context
🧹 3. Trash or debris in the parking area
Wind can push plastic bottles under tires
Parking lots with poor cleaning often have repeated debris issues
⚠️ 4. Rare concern: targeted behavior
It is uncommon, but if it happens repeatedly in a specific spot:
it could be someone in the area messing with vehicles
Even then, it’s usually nuisance behavior, not serious threat
👍 What she should do (practical steps)
Check where she parks (try a different spot for a few days)
Take photos if it happens again
Ask workplace security or building management to check CCTV
Do a quick walk-around before leaving parking area
