1. What does it mean?
차박 combines 차, 'car,' and 박, 'overnight stay.' It describes using a vehicle as the place to sleep rather than booking a room or simply driving somewhere for the day.
Also written or said as 차박 캠핑, car camping
2. The nuance
It does not necessarily mean owning a camper van, and it is more specific than a quick rest in a parked car. The expression describes a travel style, not permission to camp or park overnight at any particular spot.
3. Examples
“이번 여행은 숙소 대신 차박을 계획하고 있어.”
For this trip, we're planning to sleep in the car instead of booking accommodation.
“첫 차박이라 짐을 줄이고 가까운 캠핑장을 골랐어.”
For my first overnight car-camping trip, I packed light and chose a nearby campsite.
Sources
Korea Policy Briefing: language and culture
References support the meaning and usage. Example sentences are written for NoCapWiki.