Here are a couple ideas, one is tape and the other is a reflector. They have some great reflective tape at Home depot in the mailbox section. The inside of the cranks are a great place because of the movement. They also have the reflector shown below (mailbox section also) with adhesive tape on the back and a white frame around it that can be bolted onto the plastic gray cover found in the electrical section. The reflectors come in two packs and are cheap. I have removed the white frame. If the red reflector by itself falls off, I'll put the one with the white frame around it on with bolts.

While driving at night, I always noticed those mailbox reflectors and the ones that have the long sticks people put on the sides of the driveway, etc. They all have the same reflector more or less in them and are visible for a long ways off.