Sorry for late reply Mani Bhai ...
Just when I tried to reply, my wateen stopped working alongwith DSL ... so just now, connected my laptop through my phone ..
I used one sheet ... as I checked today, I was left with 5 sheets. Approximately, 1.5~2 sheets will be used in sub enclosures ... therefore I will try my best to finish the trunk floor and sides in 2~2.5 sheets. In case, it is not enough then may be I will buy a door kits and complete the trunk