I was always bothered by the immense size of the key fob for my 2012 Taurus, which included so many unnecessary features like buttons and a mechanical key. I wanted something small, light, and waterproof to take with me when I do outdoors stuff. I printed an upper and lower container into which I installed the guts from the factory key fob. I superglued the two halves together, then applied a few coats of Krylon Fusion Black Gloss, and then a few coats of clear acrylic sealant. I hope that has made it waterproof - but when the battery goes dead I'll have to crack the case open w/pliers.