Currently a Clean Slate

[Lotusman333]

Hi there we've had our Yellow H2 for some time now, and I finally bought it from my dad. I've decided it needs some upgrades. This is what i'm looking for advice in.
1. I want to put Subwoofers in the back of it, but I want to keep the cargo space that I have. If I put them under the 2nd row seat is there a way I can make it so the seat still folds down? Otherwise how can I mount them in there?

2. I understand some people are for, and others against Train horns in Hummers. But i'm going to put one in mine, I have visited the site Hornblasters.com, but i'm really unsure about it. Do they really have the same horns that trains have that can be heard from 2 miles away? If not where can i find a setup to do that?
Also to go along with that, can I hook it up in some way so that I can have a switch to switch the putton on my steering wheel from regular to train horn?

3. Lambo Doors. Suggestions?

I know it's a lot, but thanks for your help.