I think you would be SOL in that case.

You could loks your keys to a "normal" car in the trunk by doing the same thing.

I have just cliped my fob to a "rope chain" that I have my gym pass on. I then just throw that over my head and put it in my shirt. You can't see the FOB, and it can't fall out of my pocket, I won't frget it in the car, etc... It is with me at all times, and I can even workout at the gym with out keys in my pocket.