I believe you are still the owner of that data, but if you are holding someone's PII — which time of passage, car model and license plates can be argued to be especially with a fixed location — according to privacy regulations, they can ask a business to remove it unless they have a legally acceptable reason to keep it (eg. they hit-and-run a parked vehicle).

Now, with you likely not keeping that Ring tied to a business account, how that applies to non-businesses holding PII is a different matter.