Passive protection is what brings you to avoid the accident, like handling and so on (case in point above).
Active protection is what protects you after it hits the fan.
It's not news anymore, but shell-wise - the Tesla Model S apparently broke NTHSA's roof-crushing machine during the tests. Not advocating for one, just saying that they are all good, once you take the elefant in the room out.
And the elefant in the room is that cars are rated within their own category, and then size and weight steal the show.
I still remember decades ago when some Dunning Krugerite in the photo forum ardently boasted how the Suzuki Kizashi is the safest car to be in because it got at the top of its class. To my question whether he'd prefer to be in the Suzuki or in an (not top of its safety class) Cadillac Escalade or a long wheelbase Tahoe in a head-on crash, his smug answer was - of course, in the Suzuki. It has more stars.
I didn't persevere
However, all other things being equal - always think apples for apples. A BMW 5 series is a huge car in Europe. It's a small one here.