When your car starts to wobble at high speeds it's usually caused by either a bent wheel or out of round tire.
I would get the tires checked on the car to make sure they're not fixing to blowout. You could have a slightly bulging tire or the tire may need to just be balanced.
Take the car to a shop and have them check the wheels and tires out because if it's a bulging tire especially on the front of the car it could blow out at high speeds and cause you to roll the car and possibly get killed in the wreck.