Ok so i am going to be doing my doors and the whole car, i had a question about the doors, do i cover the outer metal surface and the inside metal pieces or do i do the outer metal and then put one whole sheet on the inner metal surface so there is only one hole (for speaker)?

 

Do the outer door panel, the one that's on the outside of the vehicle, then "seal off" the door itself, the inner panel and leave the hole for a speaker yes. If you have big holes in your doors, you would be better off if you could put a sheet metal or something strong on top of them, because the deadener may flex on those spots when you're blasting.
Do it with small pieces, this way it's easier to apply.

My doors aren't the work of art, but it is good judging from the sonic results.
http://memimage.cardomain.net/member...01_56_full.jpg
Also don't forget to put some deadening on the plastic panels.

 

Thanks alot!