So, DH teases me about it, but I've got this free app on my phone that keeps track of where I left my car. I've used it for where I left my bike too, when we've gone to festivals where the entrance is gated, and you park outside, and walk in, eat and drink stuff while listening to music, and then you have to remember where you left the bike so you can ride it home again. (example: Fat Tire Festival, next weekend!)

Karen in Boise