Front seats are locked and will not fold down to allow passengers into backseats on Mercedes CLK 320?

you have to slide the seats back and down toward the floor with the power seat option otherwise the headrest wont clear the roof and so it locks the second stage lock. Also, you need to wait for the headrest to go all the way down when you pull the handle or they won't unlock either. It's actually pretty intuitive and easier to do than explain in writing.