Tiles are small devices that help you find your lost stuff, so why not a car? If your car is stolen, how likely is it that a $20 device could help find it again?
4-pack for $70: http://amzn.to/2ys7HZQ
Tile for Keys: http://amzn.to/2yrVq7M
Tile for Wallet: http://amzn.to/2hD8c9f