S o you were driving behind a semi truck in slow traffic the other day and noticed something peculiar at the top of its tall exhaust stacks: small metal flaps that flip open with each rev of the ...

In the case of mud, this can be annoying ... them both on semi truck tractors and on the back of semi truck trailers. These big square flaps are flexible enough that they won't snap off when ...

"I'm a truck driver and was frustrated with accidentally damaging mud flaps and brackets when reversing towards low-level ...