GM proving grounds in Milford MI, has many different car washe configurations to make sure their vehicles can go through a car wash with no harm to the vehicle. In addition to testing the base vehicle, all GM authorized accessories are also tested for washes (as well as crash worthiness).
The front brush guard is rounded, and should go through ok. I have not needed to take mine through, but when the hose freezes into a block of ice, and the salt is spread out in quantities that turns everything white, I will take mine through a car wash.
Lucky for me, my neighbor's brother owns a few car washes, and he has assured me many times, that they have run all types of Hummers (H1-H3) with no problems through his car washes. Just make sure to fold in the mirrors, and make sure the sunroof is closed.
(I will say something on the H3 forum that I never dared to say on the Vette Forum, I have even run Vettes through a car wash, and guess what; it didn't leak or get destroyed.
Only when needed, and when too damn cold to wash at a quarter wash, but I did it, and it survived. )