I was going to reply to the "most heated" thread sa forums pero in the long run sabi ko that device will go the way of Zagu, Shawarma and Rice in a Box
yup smoke from tail pie causing dirt on walls , back up lights to alert in coming traffic when coming out from your slot etc.
seems logical nga
backing up the wall...well there's a cement barrier/hump para may allowance ka so you won't hit the wall and space for you to open trunk (most malls puwede 'to)
in the case of Ali Mall and Gateway mukhang preventive lang
so their wall won't get dirty