Fuel Smell..., burning? Options

[tonytutino]

OK so i've noticed when i get out of my car quickly, like right after i turn off my engine, i smell this pungent smell of something burning. i'm pretty sure its gas though. the smell also hits me if my windows are down at idle. andddd if i accelerate quickly. my gas mileage has started to suck too, i'm not sure if that has anything to do with this but i could just be running awfully rich. any ideas guys? its really frustrating.