To my amazement, it developed into a full triple arc, stretching from horizon to horizon, running through all the colors twice, and with an echoing shadow of a rainbow above it. It glowed with brilliance.
It faded back again, but still a complete bow, from land to sky and back again.
Eventually, the driver could also approciate what I'd been exclaiming over for the previous forty-five minutes. The angle of the photo is from having stuck my hand out the window with the camera to avoid windscreen splatter.
The rainbow ebbed and flowed for most of the trip, but never entirely went away until we hit the M25 and drove off in a different direction.
We'd driven towards the rainbow for so long that it felt as if we'd eventually catch up with it. We did. Here it is going along in the next lane over.
The rainbow caught in the sprays of water from our car and others after a brief downpour. Even if the optics made sense, my eyes were confused by the sight of a rainbow next to us continuous with the one in the sky which seemed so far distant.