Be smart guys. If you have to screw down or drill AT ALL, put MDF or something UNDER the carpet, and drill in to that. DONT take the chance that you wont hit the tank. You dont wanna have a minor fender bender, get a small leak, think everythings fine, and get the sunburn of youre life when that sucker lights up....

 

I had a bunch of amps screwed down in the back of my car a long time ago. Didn't know the tank was that close. My car was still under warranty then and the fuel pump went out. When they went to drop the tank down it was stuck in the car. Actually screwed in from the top.. They were pissed. Had it soldered which I later had to replace anyway..
I won't even bother to talk about the plate thing anymore. It's like anything else. It's all about how much money you got in it. You could turn a sub upside down in a cardboard box if it's mounted securely, put some high dollar equipment to drive it and it will sound good. you can buy or build a high dollar speaker box. add some fosgates and then power it up with a Kraco in dash and it will sound like do do.. There is the real answer.

 

True, a nice high dollar (which doesnt have to coincide with nice) box with a not so hot sub and amp will still sound like ****.

But, the nice equipment in a ****ty box thing, im gonna disagree on that part. If you find a way to support a W7 in a cardboard box, and drive it with a nice amp, its STILL going to sound like total ***. End of story.