A vibrant retro sci-fi scene depicting a 1950s-style diner perched on a rocky asteroid, surrounded by a cosmic vista. Sleek, chrome-plated flying cars zip through the space around the diner, their headlights casting dynamic, colorful beams across the starry backdrop. The diner itself glows with neon lights in hues of turquoise and pink, reflecting off the asteroid's rugged surface. Inside, customers in retro-futuristic attire chat over milkshakes and burgers, their holographic menus floating above the chrome tabletops. The scene is detailed with swirling nebulae and distant planets twinkling in the expansive sky, adding depth and wonder to this otherworldly 4K landscape.