I changed something in the engine area while parked up in Sainsbury's car park. I took my Apple watch off and left it on the engine cover, then closed the bonnet and drove off.
Obviously been picked up somewhere, and obviously can't be used as it's locked. This happened on 24th May.
I left a couple of signs up in that area.

I hope you get it back, would your insurance cover it or is the excess too big ? Just a thought I hope you don't get a parking ticket for going back. Lots of these places say no return within 2/3/4 hours.

I think you need to be close to the watch but I am not sure.
'When you use Find My, your Apple Watch with GPS and cellular can use GPS and a trusted Wi-Fi or cellular connection to show you its approximate location. Apple Watch with GPS can use GPS and a trusted Wi-Fi connection. Since Apple Watch Series 1 doesn't have GPS, you'll see the location of your paired iPhone or its Wi-Fi connection.'

https://support.apple.com/en-gb/HT207024

Yes, my watch didn't have GPS. I was offering a reward, but have not had any calls, so it's gone for good,
I have had scam calls and random scam text messages, so obviously someone has seen my signs.
I bought a new one with GPS and cellular so if I lose it again (as I'm an idiot), I'll be able to trace it.