It must be true cos I worked as a salesman for Volvo in the late 70s and that is wot we were told to tell the clientMy car already has them.
I think claiming them as a safety feature is a bit of a stretch - some might suggest typical car advertisers spin - an effective car heater is going to have a better effect overall.

Anyway........if you don't think they are useful can a give you a tenner for yours........that will save me a few bob.