I know nothing about patent law but this strikes me as false. I cannot be sued for turning on a radio in a vehicle that I bought or rented. I've never heard of a court thats accepted such frivolous claims either, nor of any law that asserts such.

The manufacturer of that radio can possibly be downstream sued, sure. That sounds at least plausible if they're assembling said radio without proper license for the parts. But simply using a radio in my car doesn't strike me as something enforceable nor legitimate in any way.

How do you figure a user downstream could be sued for not licensing a radio in a car they bought/rented? You're claiming we're all legitimate targets at this point in the eyes of the law (anyone using a radio in a car) so I'd like to understand this.