Please my Subaru shaken when driven on highway. it was inspected by the dealer they couldn't found nothing.  What they told me is that I should replace / change the front rotors and brake pads. I changed it, but still doing the same, whenever the odometer reach 35mph or 40 above when 'am driven. So I don't know what to do. Please anyone who have similar problem about this vehicle before. Please do not hesitate to give advise or opinion what to do. Thank you.

I've seen it before, not on a Subaru but same problem.

First make sure the wheel nuts / bolts have the right profile (cone or ball). They may seem ok and tight but they can be off center.

If you can borrow a set of wheels change the one you have and see if any change.

Balance all tires and change front to rear and see if it makes any change.

Just a few ideas.

Tyre out of balance, missing a weight?