Um, yeahhhhh...
Let's start with the owner's manual which clearly states no more than 5 MPH through water - Dude, let's be honest, you were going much faster, which is a typical reaction! If someone puts a snorkel on and thinks you can do 10-20 MPH through a puddle, you're in for a lot more trouble.
Now, lets turn to the vehicle itself. If you get into too much water, you will begin to float! To counteract this in most vehicles designed to snorkel, the vehicle is designed to sink. Two questions come to mind here: 1) do you really want to drill holes in your floorboards, and 2) do you really want to soak the inside of your vehicle with carpet, padding, seats, etc?
Bottom line, unless you're building an extreme Patriot that isn't your daily driver, as is it for everyone on here I believe, a snorkel is NOT practical or worth the money and modification. Of course, if you think it will make your Pat look "cool", go for it, but I think it will generally garner laughs. I love seeing Land Rovers and other high-end vehicles with snorkels to the roof, knowing that if they actually used it, they would total the inside of their leather-trimmed vehicle. Just my opinion...