Serhat Kurt, macReports:

Apple Apple now has 55 vehicles and 83 drivers under its permit to test autonomous vehicles, the California Department of Motor Vehicles (DMV) said in an emailed response to questions.

And:

Apple has the second highest number of self driving cars after GM Cruise,which as 104 vehicles, as of now.

I find it surprising that Apple has more self-driving vehicles than Waymo. From the Waymo Wikipedia page:

In 2018, the company placed separate orders for “thousands” of hybrid-drive Pacifica minivans and 20,000 Jaguar I-Pace electric sedans. The vehicles are intended to help launch ride-hailing services in various cities, enough to accommodate hundreds of thousands of riders each day.

That aside, it is interesting to watch Waymo (owned by Google’s parent company, Alphabet) roll out their vision, while Apple, per tradition, keeps its cards closely held.