i use i nut that i glued to the back with gorilla glue 3 of them i bolted them on the panel before i screwed speakers in 1 screw behind each speaker they are 61/2 a 4'' and a tweeter they sound really clear and for the bass i put 1 10'' a twenty tear old sass tube it hits hard and fills in good with the lows .i had 2 jls10'' at first but i wanted to keep it light and just have the room in the trunk .yes first i used the panel to mold the bottom base then i tookit from there to build the pods for the speaker and aimed them i made speaker rings first then i used those cheap spunge paint sticks that u get a home depot about 5 or ten to a pack the sticks are round i just rip the spunge of and after i had the rings angled where i wanted u used a teeshirt and stretched it over and use spray adhesive to hold it in place at the back then i fiberglassed it all in all around and used bondo also .the way i popped out the base panel in the begining was i wrapped the panel with plastic garbage bag i wrapped it and tapped it at the back nice and tight after the base plate dried i just pulled the tape off and the base plate came right off and had the contour of the panel.i used audio band speakers i know there not that good put they sound clear my next set of speakers i will use morels those are great .thanks for asking if you need to no anything else just ask .