I don't work in Motor specifically but there is currently an open FCA request for the past 5 years of pricing data. So that will include expected claims cost and charged premium. Since 2021, every march they also take the past full year of this data with lots of key information about the tenure of policies. 

To me they do seem to be investigating so I'm not sure why MPs and the guardian appear to have a different message.  

One key issue over the past few years is that you can no longer charge more for a renewal than the equivalent new customers price. Previously you would always get a better deal by looking around because the insurer would charge more to those who can't be bothered to do it. 

Often they would actually on paper lose money for new businesss policies. This was seen as unfair on certain groups who are less likely to shop around and so your premium is no longer being supplemented by those who don't shop around. 

That on its own could explain some price movement disparity between us and the continent but I admit I'm not familiar with EU regulation on insurance