“Dashcam” (0 stars out of four) was a mind-numbingly awful horror show about two friends (Annie Hardy and Amar-Chadha Patel) who embark on a road trip that turns into horrific violence and they livestream what soon turns into the most terrifying night of their lives (and maybe yours). Hard to tell what’s most unwatchable in this film, between the headache-inducing handheld photography, Hardy’s screaming (and rapping at the camera!), or the cluttered computer visuals onscreen but either way it’s an unendurable mess. A new low of found-footage horror films and also for Blumhouse Productions.