our new car has plastic main lines for brakes, driver says pedal feals soft ,our old car has steel lines is this common for poly lines to feal soft pedal Flex ...
...

I have had them on 2 different cars. Both cars had nice firm pedal. Check pedal mounts and caliper mounts make sure they are not moving. I had a so called shop install hanging pedals in a car and the pedal felt mushy. Discovered the whole assy. Was moving.