回复：回复：几种轿车窗框的结构测试

Not a good example to express your doubt, any car maker will try any effect to cut expense if possible, bmw even uses vinyl seating on 5 series.
the video is about uni-frame window vs welded frame window in general, not an extreme case vs another extreme case. do you believe those car makers who cut rear protection beam will provide equally strong frame to the one on your bmw?