Complex sentence: She initially tries to escape using a computer rescue help system, but the system takes too long and she gets out of the car using its open sunroof, before venturing into the jungle, not to be seen for the rest of the movie.
Split into simpler sentences: She initially tries to escape using a computer rescue help system, but the system takes too long and she gets out of the car using its open sunroof. She then ventures into the jungle, not to be seen for the rest of the movie.