what would be a good and easy unit to use/install oneself as a backup sensor, to determine distance from wall or other obstacle (ie. pillar in public parking garage or other car)?
I'm not afraid of doing a little drilling myself but in visiting the local napa autoparts (also advanced auto parts), they don't really know anything about the products to tell the customer, just point to the box on the wall
I don't need a camera, just something that would tell me how far the rear bumper is from the wall