Some of the most popular higher end cars on our roads in the UK are Land Rovers and Range Rovers (and similar sized less high end SUVs from Kia etc), all of which are wider than an X.
I've driven some really rural narrow roads in my Range Rover and have never encountered a bridge or road I can't use... would be keen to read a source on that bridges thing as it's completely new to me and is failing my sniff test.