Long term report: Lexus IS300h

My mother-in-law has a 2011 Mercedes C-Class estate and a Nokia 200 phone. Now although new, the Nokia 200 is no cutting-edge device and her car is approaching five years old. And her phone pairs with her car without a problem. But try as I might, I cannot get her phone to talk to the Lexus. I can pair my iPhone, and other devices, but not this. You might perhaps expect older technology to struggle, but surely our new Lexus would be a little more robust with its connectivity?