How to test if your box will fit?

[rosshimself13 10+ year member]

at first i was going to say uhh tape measure, however since you fail at measuring go to lowes home depot or wherever they have sheets of stryrofoam insulation its not free like card board, but it may be what you need

 

[bhsdriller 10+ year member]

If you have a small trunk openening, build the box inside the trunk

 

[Carnivorous18 10+ year member]

If you have a small trunk openening, build the box inside the trunk

I would. But this is something I want to be able to remove incase I get another car or I need to access the spare tire or whatever. I already got the foam board from Michaels (cheapest place by far unless you get it 1/2" thick). Working out really well. I know now definitely I cant fit a box with 15.5" height, so ill be testing 15" after I finish cutting it down