Biofuel cars and smell

First, the neighborhood, as I was driving home from coffee, smelled like fish the kind of foul smell you find in a dirty fish & chips restaurant. I couldn't figure out why.

Turns out, the car in front of me was an old Mercedes that said the car was running on biofuel.

Next, going downtown, I smelled the odor of rancid fries in the air over a two block stretch.  This time it was another Mercedes running on biofuel. Proud biofuel signs in the window and the license plate.

I hope that this smelly eco-solution doesn't expand.  If it does I hope the biofuels smell more like truffle oil or lavender than like a Chinatown kitchen grease.