1. Open Game Master - Spawn a BTR-70 alongside a playable entity
2. Enter the BTR-70 as the playable entity (Any position with access to the right door)
3. Exit the BTR-70 via the right door
4. Panic as you are consumed by quick sand

This outcome most likely depends on where the vehicle is located on the terrain so if you're unable to reproduce, try and move the vehicle around in various areas before getting out again.

In my case, this was tested at the road bend @ 022 012.

Video Reference 1: https://www.youtube.com/watch?v=ChkKohp590w
Video Reference 2: https://www.youtube.com/watch?v=VpqRIZhaBDo

Noticed the ejection animation 'distance' seems to be further on the right door in comparison to the left door for some reason which 'may' be the cause.