In the US as long as you don't touch the emissions system you'd be hard pressed to run afoul of anything as long as you're not taking some specific look and cha

In the US as long as you don't touch the emissions system you'd be hard pressed to run afoul of anything as long as you're not taking some specific look and chasing it to the extremes (super tall trucks, cars with tires sticking way out, absurd headlights, etc).