Baboons like cars. Its probably their novelty that attracts them. You've all seen what they've done on YouTube. Those incidents are outliers, as you've probably guessed. Normal baboons don't want bras, they want food.
Or they want a fun new playground. Cars are like a giant toy: they have all this stuff sticking off of them that you can break, plus some entertaining moving parts. Look at it from a baboon's perspective: they spend all day romping through the forest, jumping up and down on logs, rock, and branches, breaking anything they want, and of all those thousands of objects, no one cares a lick.
Rainer and I ran into an isolated car while following the baboons, one innocent day. As I said, baboons like cars, so the juveniles were already swarming over the automobile. Then I noticed something odd going on... or at least I perceived it to be odd that the time.
These baboons really liked licking this car. I'd never seen this before.
I'm not sure what the baboons got out of this exchange. The car was covered with dirt and dust from the park, and soon to be covered with baboon feces and urine. The all that the car brought with it that was not already readily available to the baboons were particles from the streets. And of course, the paint itself... I wonder...
When baboons lay down, they move heard first, so that the forehead or cheek bumps into the surface before the rest of the body plops down by it. One of them sat on the roof and half-lay down so his head was pressed into the top of the roof and his tongue fell out of the corner of his mouth, furiously licking at the paint job.
"Depraved is the only applicable word which can satisfactorily describe this baboon," I narrated. "He looks as if he were a fiend under the influence of this car's hallucinogenic paint, and his mind is centered on one thought: More."
The baboon raised himself from his half seated position and stared at me indecipherably.
"I don't think he liked what you said," commented Rainer.
Circling around to the rear, I saw a baboon had torn a sticker free from the back windshield, and had begun to eat it. "Congratulations," I offered the absent owner, as the sticker was slowly devoured. "You're been promoted. You're no longer a learner driver."
And now, the truth. I've still got no better idea why they lick cars. They lick the windows too. Novelty is about all I can imagine, and baboons have no concept of disgust. They look at the new cars, touch them, smell them, hear them, so why not taste them?