I suggest jacking up the front of the car just enough to lift the tire off the ground, then spin the wheel/tire by hand, and while spinning, get down eye level with the top of the tire and look for an out of round condition. Most tires will be a little out of round, but if you see something odd, like a sudden dip or flat spot, you'll know it. when done with that, turn the the steering wheel so the tire surface is pointing out, then hand spin again and watch the tread to make sure it is rolling straight. Sometimes I've seen tires that didn't not seat correctly on the wheels in one spot, or that were molded wrong, causing the tread to have a wobble.
Lastly, if you spot a wobble or high/low spot in the tires, there is also a possibility that you may have wheels that are out of round, which will need to have the tire dismounted and checked and measured.
Which brand and model of wheels and tires did you get? Some tires may appear to be a great value, but the issue you're left with could be cheaply made tires. I can tell you that Michelin tires are probably some of the truest running tires you can buy, and if the issue turns out to be the tires, replace them with Michelin.
2015 Mustang GT PP 401A Black | Roush Supercharger