I got the curb alert that came with the pigtail with a 10 amp fuse in it so that it can be plugged in the fuse box in the footwell. Instructions said there was an empty socket, but in my car (a 1999 conv.) the socket referred to was in use and there was no empty socket (other than one that had no power going to it). I found another socket that had a 10 amp fuse in it where I could plug the pigtail. I removed the existing fuse and plugged it in to the pigtail next to the 10 amp fuse that was already included in the pigtail. Right now I cannot remember which socket I plugged into but it was down near the bottom of the fuse box. It may control the interior lights when the door opens. The unit seemed to work fine except that when I walked past the front of the car after it had been parked in the garage for quite some time, I could hear the beeper go off. Some time later when I walked in front again to see if it was still doing it, it did not beep. Is what i did ok, or should I just place the control box i the engine compartment and hook up to the positive connection at the fuse box near the battery and ground to an appropriate place?

 

I would find a swicthed power source. Just use a meter/test light and turn the car on and while probing the fuse box until you find one.

 

If I do that, when I pull the existing fuse to plug in what i call the piggyback, should I then put the fuse I pulled into the available space on the piggyback in addition to the fuse that is already there?

 

I would piggyback it to the non-powered side of the fuse. You can leave the fuse it came with intact for added protection.