I'm seeing a trend around here with the kids driving around in 3/4 and 1 ton diesels with vertical stacks coming out through the bed behind the cab. I've also seen some of them coming out beside the back corner of the cab and going up from there. They look like the semi truck ehausts that you see.

So I figure the main purpose of this is looks. They want it to look cool, and this is the current cool. Some of them have put different injectors in and there trucks emit a LOT of smoke. They also have a different sound to them, not like the diesels of the past that I've been around.

Does anybody know the legality of this? Do they have mufflers somewhere before these stacks or does running the exhaust straight up eliminate enough of the sound pollution? Is there any concern that a passer by (in a parking lot for instance) might brush up against this hot exhaust pipe and burn themselves?

I'm not complaining, and I'm not for or against, just curious. Thanks.