Dear Truck Dude,

You were the one on 15th Avenue about two weeks ago on a Friday. I pulled up behind you around Karluk Street. I had a headache. You had plastic man parts hanging from your tow hitch.

It might not have bothered me, as I have seen this kind of thing before, but it wasn't just you, it was also the dude next to you. And so I was trapped, staring into a vortex of swinging truck junk until the light changed.

My aching brain filled with one alarming thought: Is this going to be a trend now?

I mentioned your bumper ornament to a coworker a few days later. He said, "Oh, you mean TruckNutz." And so I Googled. It was a trend. The Nutz, which are widely available online, became a big thing last year during the presidential election after someone suggested Barack Obama get some so he could better relate to rural America. And a few states moved to ban them from the roads. They were kind of 2008, but like every other thing that becomes a thing Outside, it appeared they were catching on here 2000-late.

I was left to wonder, Truck Dude, what are you trying to say? Is it a declaration, like "Here in Alaska our vehicles are so manly they have privates?" Or a come-on, like, "Hey ladies, I'm awesome, my car has simulation man business!"?

I decided to ask my dad.

"Maybe it's trying to communicate superior masculinity," he offered.

I called around to truck shops. Turns out TruckNutz or Bulls Balls, as they are also called, aren't easy to track down. I finally found several sets at Car Toyz on Fifth Avenue. Endowing a truck costs about $45. The goods are available there in black and chrome.

People often steal them, according to the shop owner who didn't want to give his name. He wasn't into them personally because he has a 2-year-old who asks a lot of questions. But he's a businessman and there's a market. I asked what he thought they were trying to communicate. He told me to ask the guys at the truck shop next door.

So I went to Underground Performance, a shop that specializes in custom trucks, where I found Jeremiah Crawford, age 21, sitting behind a desk in a lobby. I wanted him to help me understand you, Truck Dude, but the first thing he said was, "We don't understand that side of truck culture, either."

Crawford has a 1987 Toyota Land Cruiser, which he uses to drive off-road. He pulled up a picture of himself in a beautiful mountain valley. That's why he's into trucks, he told me. Then he thought a minute, and offered a thesis.

"Society is over-sexualized," he said, leaning back in his chair. The Internet makes pornography abundant. Young people have no qualms talking about it. No matter what vein of culture you're looking at, "it's just gonna come out," he said.

"So the TruckNutz are an extension of an over-sexualized society?" I asked.

"They're an extension of something," he answered.

About then a customer came in and they broke into conversation about lifts, shocks and injectors. Toward the end, Crawford told the guy. "Your drive shaft angle's gonna be money."

He suggested I try to think about it differently. Maybe the Nutz are just an expression of personal creativity.

"It could be taken as art," he said.

I was driving home after that when my brother called from college.

"You're over-thinking it," he told me. "It's just funny. Truck balls. Say it. Truck. Balls. See, you're trying not to laugh, I can tell."

Maybe I was over-thinking it. Maybe it was a little funny, in a 14-year-old boy way, but that wore off quickly. Then it was just plastic testicles hanging from a stranger's car. My mind wandered to a trip I took in high school to Florence, Italy. I travelled with my grandmother, who was from there, and we spent a day visiting a number of nude statues, including "David" by the Renaissance sculptor Michelangelo.

A few days later, I was returning from a short errand when a tiny Italian car swerved into my path. The old man inside called me over. I stupidly went to the window. He was naked from the waist down. Horrified, I ran home and told my grandmother.

"Why are you so upset? It's a naked man. So what?" she shrugged. "I took you to see the David yesterday. What's the difference?"

Then she told me to go get ready for dinner.

There's a difference, of course, Truck Dude, between Michelangelo and an Italian car flasher, between what's art and what's just obscene, but it occurred to me that Nonna had a point. You and the flasher are looking for the same thing: a reaction. Sure, you're a little shocking and a little funny. But after that fades, you're just another dude with a truck payment, looking for attention. And in that way it's kind of sad.

So drive on, Truck Dude. I hope you find what you're looking for. And next time I'm behind you, I will feel a little bit of pity right before I look the other way.