What removeable dashboard cameras befit car renters? [closed]

My grandparents rent cars whenever they travel to other Canadian provinces for roadtripping. They need a dashboard camera, as someone tried to defraud one of her friends like the following:

As CBC News reports, in at least one instance a driver's dashcam may have saved him from falling victim to insurance fraud. In that case the dashcam recorded the man's vehicle being struck, seemingly deliberately, by another vehicle. While it was impossible to say for sure in that case whether the crash was an attempt at insurance fraud, industry experts say dashcams are proving useful at protecting safe drivers against unscrupulous or dangerous motorists.

This Reddit post is 1 year old, and this 3 years.