I'll see what I can find...I won't be back until June though. However, do you recall what color the pump/nozzle was? It would've been green if it was diesel. The unleaded options would be yellow or red.

EDIT: I can't seem to find anything else. The picture above is from a Puma Gas Station right outside of San Juan. However, most Google searches have pictures from other parts of the world. But after re-reading everything and you mentioning that you never refilled the vehicle (other than the $10), there is a possibility either someone put something in the gas tank prior to your departure that day or there was a significant mechanical problem with the vehicle. It may also be plausible that the $10 of gas was actually diesel and when the fuel system was checked, they found some diesel in the tank. The combination of incorrect fuel and an engine problem made matters worse.

Could you elaborate on the rental you had? Was it a Dodge Caravan or Toyota Sienna?

Also, for everyone that keeps claiming that you can't stick a diesel nozzle into a gasoline fuel-filler neck, read here: http://www.flyertalk.com/forum/other...ge-charge.html