The Garmin Mini 2 is tiny enough to disappear behind your mirror. Pairing it with Garmin's OBD2 constant power cable means clean installation and parked-car recording — without splicing a single fuse.
This install in a 2015 Passat covers placement, cable routing along the A-pillar, and plugging into the OBD2 port under the dash. Product links are in the YouTube description.