I have had a satnav guide me up the side of a mountain, on a "road" that became narrower and more unmade as I drove, until it resembled a goat track and I fetched up against a locked metal gate with a forbidding sign on it.

I spent 15-20 minutes executing the tiniest of incremental movements back and forth, turning the steering wheel as I did so. Finally I had manoeuvred the car to face back down the track.

I've also had a satnav lose an entire suburb - the very one to which I was driving. It was a ferociously hot day, and as I drove over the Westgate Freeway my iPhone flashed distress signals and switched itself off. (I was trying to use the iPhone's map app as a backup satnav to find the vanished suburb.) That was in the day when iPhones ran hot and executed terrifying shut-down procedures in the heat.

Satnavs have also tried to guide me through streets with changed traffic conditions (no right turn, no through road, etc), and through savagely unmade roads where a precipitous drop on the left prevents moving over for any oncoming car, so that's a bit of a dance in itself...

I now have three satnavs, in case one of them wants to play games with me: inbuilt car satnav, voice-controlled satnav, and iPhone satnav (no longer likely to immolate itself).