Logan Kart 8 is a slightly janky Mario Kart fan game that features an entire track set inside a soda machine. I’m not an expert in Logan Kart lore, so it’s difficult to say whether the racers have been shrunk or if it’s just a really big soda machine. Ask Waluigi.
Just for fun, here’s a video of me racing a lap around the Waluigi Vending Machine map.