subwoofer ?

how can I make subwoofer box for the trunk of my models(my biggest prob is to make the sub)

i would make a small box out of plastic, and cover it with the carpet u can get for models

as far as the sub, i dunno, but try and make a grill to go over it, that would help avoid making an actual sub.
good luck

You should use some old headphones or smtn and build a box for its size