There's been some talk about it in the Garmin forum and in other online reviews. It seems to have it's own bag of issues so research well before buying.
The Nano/WR-1 was a neat little cam and overall a good value for the money; I'm a bit sad to see it go but technology has marched past it as it will with every cam eventually. Are you sure there's not something new moving around where you park, a flag perhaps? Even a blinking LED or light can set off motion detect inadvertently.
The form factor is slightly different but you might want to have a look at the Gitup F1C, another small footprint cam like the Mobius but with much better specs, performance, and supercaps to ensure a long life. The Mobius Maxi might work for you but it's not well-developed and some folks have had issues with it. The original Mobius is better daytime than the Nano but it's old hardware is hardly acceptable at night nowadays. I don't know of any other small-footprint cams save for the K2S dual-remote which is a 2-channel system but with the smallest cams around.
Phil