I need some help on ideas to secure my subwoofer box in my trunk. - EvolutionM - Mitsubishi Lancer and Lancer Evolution Community

Ok... so i've got a pair of 12" boston acoustics pro series subwoofers and a SoundStream Reference 500s amp running at 1 ohm and the subs are mounted in a sealed enclosure. I had them previously in my Audi A4 and luckily the Audi had 4 bolted in metal hoop type attachments on the floor of the trunk for using their tie down cargo net, etc. I ended up putting two O ring bolts into both the left and right side of the box and used a steel quick release thing from home depot to secure the O rings to the tie downs built into the car.

Now... of course the Evo doesn't have tie downs on the floor of the trunk and i'm trying to figure out how i can secure the sub box from moving around, plus i'd like to keep a similar configuration to the Audi since i can easily remove the sub box to make room if i need to carry something or if i'm at the track.

Have any of you drilled holes into the metal floor of the trunk under the carpet to make such a tie down? I'm not sure what is exactly underneath the area where i'm considering doing this and i'm sure the fuel tank is further foward under the rear seat if i recall correctly. I just don't want to punch a hole in the tank and cause a disaster.

The box itself is 28" long, 15" high, and 12.5" deep. Here is a photo of it when i had it installed in my Audi.

I'm not sure where i'll mount the amp yet either. But i'll deal with that in time.

Thanks in advance!

-Andrew