Yesterday I watched a vlog by the famous Amanda Congdon as part of her Amanda Across America series. (I confess that I have only just tuned into this vlog and don't know what her objective is yet...)
She interviews a guy who runs his car on bio diesel and specifically on the used oil from restaurants. He comments that people in cars behind him can be seen to be looking around to see where the food is being cooked because his exhaust fumes smell of the type of restaurant he got his oil from. If it's from McDonald's then it smells of burgers and fries and if it's from a Chinese restaurant then it has an Oriental cooking smell. What an amazing by-product smell from a car instead of the standard toxic fumes.
I'm guessing that in the future you will be able to custom select the smell that you want your exhaust to have by perfuming the oil it burns with your favorite scent. What would you choose as the scent for your exhaust? Would a hot rod be allowed to exude lavender scented exhaust or would other enthusiasts turn their noses up at this? Could a monster truck expel "hint of rose" or evening primrose? Or do we need Old Spice and musk for that?
What about a Harley Davidson? I have no idea what scent the exhaust of a Harley should be matched with... Any ideas?