My mustang is shaking on the freeway when I maintain a high speed, it’s a newish car with only about 46000 miles. Could it have anything to do with wheels and suspension, or is this a bigger issue?
Front wheels might be out of balance. If your are starting to feel vibration at 50-65mph most likely wheels are out of balance.
I'd start with the suspension and tires at first, to be optimistic. I had pulling issues in my avalon on the highway that was solved with new tires and an alignment. Check the tires, have the car aligned if needed, and take a look at the suspension system. If anything is really worn out it might be impacting the way your car handles at a high speed. Do some light research into your car, and see if it is pretty common issue and what other people are saying.
