NOS - Nitrous Oxide

Hello, I own a 2000 V6 Mustang Convertable (auto trans). I have recently been looking into various ways to increase the speed of the car. Currently it has 190 hp. It is not doing it for me. I need more power. Here is the catch, i need something that is not going to be noticable, because certain familymembers are prohibiting any thing that has to do with speed... dont ask. That is why i have the v6. Now i was reading about NOS.. Does anybody have any experience with it? good idea/bad idea? any other idesas for hp? please, any help would be greatly appreciated!!

Thank You!
Jon