True..actually Batch 1 also..last time SMB214K had this problem
also...loud bang everytime the door open...
SMB3501L one was really loud..could hear clearly even on upper
deck...
Batch 1 MANs occasionally share the same problem, but they are
mostly fine, making them the best batch with proper doors...
SMB3522B's doors are super loud, like smashing the side of the bus
when closing.