It's conceptually pretty similar to cell tower dumps, where they ask for all data from a cell tower during a particular time frame. This was recently ruled unconstitutional (https://www.courtwatch.news/p/judge-rules-blanket-search-of-...), but they used it for like 15 years before that (https://arstechnica.com/tech-policy/2013/08/how-cell-tower-d...). I can imagine blanket car footage dumps working for a similar amount of time.