You spot it the second you walk past the garage. Castiel’s car is a mess. Dirt caked along the bottom, bird droppings on the windshield, and a suspicious crust of bugs along the grill. “Hey, Cas? I think it’s time for a car wash.”

“Is it necessary?” he asks, eyeing the car like it might bite.

You nod, already grabbing the keys. “I’m taking you to a drive-thru car wash.”

His brow furrows. “Dean says no machine can care for a car like the hands of its owner.”

You roll your eyes, laughing. “Yeah, well, it’ll be fun. You’ll see.”

So you drive. Cas rides shotgun, watching you closely, asking questions like “Will the vehicle remain stationary?” and “Is this safe for the paint?” You reassure him, all while pulling into the queue. When you finally roll onto the tracks and the car starts moving on its own, his eyes widen. “It’s… self-propelling?”

You grin. “Kinda.”

The first spritz of water hits the windshield, followed by a cascade of rainbow-colored foam. Cas leans forward, mouth slightly open in awe. “Is this… soap? Why is it colored?”

“Just for fun,” you reply, watching his wonder with a warmth blooming in your chest. The big rubber brushes start spinning, slapping against the sides of the car with heavy thwumps, and Cas jumps slightly. Then reaches for the window button.

“Cas! No! Don’t-” He freezes mid-motion. “You’ll get soaked. It’s a car wash, not a baptism.”

He nods slowly, settling back in his seat, eyes still tracking the brushes as they move. “Why is the rubber machine… spanking my car?”

You snort. Hard. “It’s not spanking it, Cas. That’s just how it scrubs the dirt off. Think of it like… a giant loofah. For cars.”

He stares at the brush with narrowed eyes. “It seems unnecessarily aggressive.”

“Maybe,” you shrug, “but it works.” After the dryers, you finally pull out into the sunlight, the car gleaming and spotless, Cas turns to you with genuine appreciation.

“That was… an experience,” he says solemnly. “Can we do it again”