Is there any standard or rating for comfort of popular cars seats?

A Micra sounds like a really small car. If so they're going for fuel consumtion and I doubt they'd put higher end seats in. My friend had a Kia a few years ago, the bottom of the line type, brand new, and sorry but it was really uncomfortable compared to the cars I had, but mine were always a little higher end type cars. Like American, even the boats!